taxonID	type	description	language	source
03927A32492FFA35FF5AFCE3FD02FEA3.taxon	description	(Figs 1 - 3)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492FFA35FF5AFCE3FD02FEA3.taxon	description	DESCRIPTION Cuticle (Fig. 1 A) smooth on capitulum, except for minor transverse grooves near aperture, and wrinkles on peduncle, not pilose. Aperture nearly half length of capitulum, folded. Scutal area inconspicuous. Carinal margin of capitulum with two conspicuous triangular projections, one at middle of capitulum margin and another on capitulum base, both projections with distinctly hyaline apex. Peduncle cylindrical, almost length one-third of capitulum, with one obtuse projection on middle of carinal margin. Appearance of carinal projections are progressive with growth; smaller specimens may have only uppermost projection and intermediate size specimens may have only two carinal projections (Fig. 3). Labrum (Fig. 1 B) prominent, with one row of equal teeth (33). Palp (Fig. 1 C) acuminate with long pinnate setae on distal half and few short simple setae on proximal half of inner margin. Mandible (Fig. 1 D) with three acute teeth and pointed denticulate lower angle; distance between first and second teeth twice distance between second and third; second and third teeth with upper margins slightly denticulate. Maxilla I (Fig. 1 E) with three large spines on upper angle, followed by wide notch with few small spines (four to five), and lower squared projection with several (20 - 19) unpaired medium to small spines. Maxilla II (Fig. 1 F) bilobed, anterior lobe large, nearly squared; posterior lobe small, rounded; both covered by several long simple setae. Cirri with article setation of lasiopod type. Cirrus I (Fig. 2 A) with unequal rami, anterior ramus two-third length of posterior ramus; shorter ramus with wider articles than those of posterior ramus, both rami covered by numerous simple or slightly pinnate setae; articles of protopodite with plumose setae on postero-distal angle. Cirrus II rami subequal, but articles of anterior ramus much wider, with simple and long pinnate setae. Cirri III and IV with rami equal in length and width. Cirri V and VI (Fig. 2 B) with anterior rami long and posterior rami greatly reduced, approximately one-third length of anterior rami. Median articles of cirri V and VI 1.7 time wider than long (Fig. 2 C), with one pair of long simple setae, more than four times width of article, and two pairs of short simple setae; postero-distal angle with one-third simple setae. Articles of reduced rami approximately six times longer than wide (Fig. 2 D), with one small seta on antero-distal angle and few setae on postero-distal angle. Caudal appendage (Fig. 2 B, E) multiarticulated (eight to nine articles) approximately equal to length of protopodite of cirrus VI, with setae on distal margins. Number of articles of cirri I-VI and caudal appendage is presented in Table 1. Penis short, covered with fine setae.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492FFA35FF5AFCE3FD02FEA3.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492FFA35FF5AFCE3FD02FEA3.taxon	description	There are no difference between the appendages of eastern Atlantic specimens of Broch (1927 b) and the specimens studied herein, except they have a larger number of articles. Darwin (1852: 166) described in detail the appendages of specimens from the West Indies. Of this description, I could observe only differences between the mandible and cirral counts. The mandibles described by Broch (1927 b) and by myself from the eastern Atlantic had the upper margins of the teeth denticulate. Furthermore, Darwin’s (1852) article counts are larger than those of mine, but his caudal appendage has fewer articles. Darwin’s larger specimens was about 7 mm in capitulum length, the one figured by Broch about 6 mm (inferred from his pl. 4) and mine 5 mm. Ross (1975: fig. 1) figured the appendages of H. cornuta from deep water in the eastern Pacific. On the intermediate articles of his specimens cirrus VI has small spines on the lateral surface which are absent in the present specimens and the article counts are far greater. Therefore, there are some differences between the specimens from the Atlantic (East and West), Pacific and Indian oceans. I cannot propose if these differences are populational or specific variations but the latter seems more likely. Several specimens from these localities must be studied to solve this problem. Hutchins (1952: 194) recorded H. cornuta fouling buoys, based on the unpublished data of I. M. Newell, from Woods Hole Oceanographic Institution. The depth range of H. cornuta does not encompass shallow waters where buoys are found. Therefore, this is probably a misidentification.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA35FF4DFEB8FBBBFDC0.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	description	(Figs 4; 5)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	materials_examined	TYPE MATERIAL. — Holotype: 1 hermaphrodite, SEA- MOUNT 2, stn TS 267, 34 ° 22.50 ’ N, 30 ° 22.50 ’ W, 2235 m, tl 23.5 mm (MNHN Ci 2825); paratype: 1 complemental male originally attached to the hermaphrodite, tlp 1.0 mm (MNHN Ci 2826).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	etymology	ETYMOLOGY. — Named in honor of Dr Michel Segonzac, who was largely responsible for making them available for this study.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	diagnosis	DIAGNOSIS. — Capitulum with irregular deep and wide grooves; aperture more than half length of capitulum; carinal margin without crest, only a wide, angled region basally. Peduncle almost one-third length of capitulum. Cirrus I with anterior ramus three-quarter length of posterior ramus. Median articles of cirri VI almost three times wider than long, having short, wide seta posterior to major apical setae of anterior margin; distal margin with simple scales on posterior half.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	description	DESCRIPTION Cuticle (Fig. 4 A, B) with irregular deep and wide groovesonthecapitulum, especiallyonesurrounding aperture; transverse grooves near aperture, wrinkled near aperture and on peduncle, not pilose. Aperture (Fig. 4 C, D) more than half of capitulum length, folded. Scutal area inconspicuous, without crest. Carinal margin of capitulum without conspicuous crests, only a wide and angled region basally. Peduncle cylindrical, almost one-third of capitulum length. Labrum (Fig. 5 A) little prominent, with one row of equal teeth (± 20) and some smaller teeth (± 4) on lateral surfaces. Palp (Fig. 5 A, B) long, acuminate with several long simple setae on distal half and on inner margin. Mandible (Fig. 5 C) with four acute teeth, last on rounded, sparcely denticulate, lower angle; distance between first and second teeth twice or less distance between second and third; first to third teeth with lower margin having strong, sharp denticles; second to fourth teeth with upper margins slightly denticulate. Maxilla I (Fig. 5 D) with two large and one medium spine on upper angle, followed by wide notch with few fine, medium spines and strong, small spines (four to five), lower squared projection with numerous (20 - 30) unpaired medium to small spines. Maxilla II (Fig. 5 E) bilobed, anteri- or lobe large, slightly notched in middle, nearly quadrangular; posterior lobe small, rounded; both covered by several, long, slightly pinnate setae. Cirri with article setation of lasiopod type. Cirrus (Fig. 5 F) with unequal rami, anterior ramus three-quarter length of posterior ramus; shorter ramus with articles slightly wider than those of posterior ramus, both rami covered by numerous simple or long pinnate setae; articles of protopodite with plumose setae on posterodistal angle; one filamentary appendage at its base. Cirri II with subequal rami, and cirri III and IV with equal rami, both having simple and long, slightly pinnate setae. Cirri V and VI with anterior rami long, posterior rami reduced, approximately one-third and two-fifth length of anterior rami, respectively. Median articles of cirri V and VI (Fig. 5 G) almost three times wider than long, anterior margin with one pair of long slightly pinnate setae, four times width of article, and two pairs of short simple setae, and one short strong seta posterior to large setae; postero-distal angle with one to five simple setae; distal margin with simple scales on posterior half. Distal articles of reduced rami approximately two times longer than wide, basal articles as long as wide, with few setae on distal margin. Caudal appendage (Fig. 5 H) with 13 - 15 articles little longer than protopodite of cirrus VI, with setae on distal margins. Number of articles of cirri I-VI and caudal appendage is presented in Table 2. Penis short, covered with fine setae. Complemental male only reduced in size, with fully developed cirri.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32492BFA39FCB9FD1AFDB7FE43.taxon	discussion	REMARKS The single specimen has a small complemental male attached immediately below the aperture. When examining the specimen I had doubts if it was actually a male or a juvenile which attached to the first one. The position where it was fixed, just beneath the aperture of the hermaphrodite strongly suggests it is a male. Otherwise the hermaphrodite was incubating several nauplii. Kolbasov & Zevina (1999) described a species of Paralepas which has the first complemental male known for the family. This present find suggests that complemental males are perhaps more widely distributed in the Heteralepadidae. Heteralepas segonzaci n. sp. was collected at a greater depth than H. microstoma, which first alerted me that it was probably a different species. I first thought that the grooves on the capitulum were only generated by external factors instead of by its own growth. None of the other species of Heteralepas have these deep irregular grooves on the capitulum. On its left side, a rounded scar is due to the presence of a serpulid tube, but the other grooves especially a large one posterior to the aperture does not appear to be the result of settlement of other animals or by predators. Besides the grooves, the aperture size, the absence of crests and the peduncle size distinguish this species from H. microstoma. Aside from the characteristic reduction of the posterior rami of cirri V and VI, the other characters of mouth and thoracic appendages appear to be very conservative in Heteralepas species. Observable differences appear to be only the relative size of the cirral rami and caudal appendages, the number of articles and the ornamentation of the articles. Presently, however, it is difficult to review these characters because most of the appendages of the species are poorly or not described at all.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324927FA39FF60FD09FDA6FA80.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324927FA3CFF7EFA55FEE5FE43.taxon	description	(Figs 6 - 9) Anatifa crassa Gray, 1848: 44, pl. 3, figs 5, 6. Poecilasma crassa – Darwin 1852: 107, pl. 2, fig. 3. — Barnard 1924: 52. — Zevina 1982: 96, fig. 85; 1983: 1635; 1990: 184. — Southward 1998: 18.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324927FA3CFF7EFA55FEE5FE43.taxon	description	MARVEL, stn PL 1201, 37 ° 50.54 ’ N, 31 ° 31.22 ’ W, Menez Gwen, 850 m, 2 specimens, tl (cl) 6.7 (4.5) to 7.1 (4.4) mm (MNHN Ci 2829). DESCRIPTION Capitulum (Fig. 6 A, B) strongly globose, asymmetric, with white plates; occludent margin slightly convex, nearly straight at upper portion; carinal margin convex. Peduncle (Fig. 6 A, B) short, usually about half the capitular length. Scutum (Fig. 6 A, B) very convex with fine growth lines sparsely marked and thin longitudinal striae; apico-basal ridge prominent, usually with groove running along carinal side. Tergal portion with nearly straight area between apicobasal ridge and line between umbo and carinal apex, another strongly curved portion between carina and peduncle. Carinal margin convex, tergal straight, occludent margin straight at upper portion, slightly convex below. Internally with thick rim basally curving toward occludent margin, without umbonal teeth. Scuta of different sizes and curvatures, less convex with umbonal portion overlying more convex one. Tergum (Fig. 6 A) small, positioned between apico-basal ridge of scutum and carina apex; usually very eroded. Carina (Fig. 6 A, C, D) strongly curved at basal half, keeled basally, nearly flat apically; apex not inserting between terga; lower end with tooth projecting inward. Labrum bullate (Fig. 7 A) with one row of nearly 80 acute teeth. Palp (Fig. 7 A, B) acuminate, short, covered by long finely pinnate setae on inner margin and setulae on outer margin. Mandible (Fig. 7 C) with four equal teeth, denticulate on lower margin, lower angle produced with small tooth; large number of simple fine setae on lateral, lower and dorsoproximal margins. Maxilla I (Fig. 7 D) with notch and lower portion produced; upper angle with one large and strong spine and five to seven medium-sized spines, below notch almost 20 - 22 small spines; large number of simple fine setae on lateral and lower margins. Maxilla II (Fig. 7 E) quadrangular, with few simple setae, more densely present on upper portion. Cirri of acanthopod type; articles with few finely and relatively small pinnate setae on anterodistal angle and several stout spines on postero-distal angle, which may be distributed in transverse row near distal margin; spaces between spines usually with multifid scales (Fig. 8 B, C). Cirri I (Fig. 8 A) and II (Fig. 8 D) with proportionally short rami and large protopodites; rami unequal 3 / 2 and 4 / 3, respectively. Cirri III to VI (Fig. 8 E) with subequal rami, length of medial articles equal to its width. Caudal appendage (Fig. 8 E) smaller than coxopodite, uniarticulate, with tuft of long setae distally. Filamentary appendage large, wide, projecting anteriorly from base of cirrus I. Number of articles of cirri I-VI and caudal appendage is presented in Table 3. Penis annulated, covered with fine setae.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324927FA3CFF7EFA55FEE5FE43.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324927FA3CFF7EFA55FEE5FE43.taxon	description	Darwin (1852) described briefly the cirri of P. crassa, but Pilsbry (1907 a) did not describe them for P. inaequilaterale breve. The cirri of P. crassa are typically acanthopod, very different from the ctenopod type of P. kaempferi and P. inaequilaterale. Other characteristics of P. crassa which should be considered are the relative length of cirri I and II. Both rami have very short rami and long and very large protopodites. Visscher (1928: 199) recorded P. crassa as a species fouling ships, which was cited in the list of fouling barnacles by Hutchins (1952: 194). P. crassa is a deep-sea species and does not occur in shallow waters. Essentially all records are between 217 and 1386 m, although Weltner (1922: 78) recorded it at shallower depths (25 m). Therefore, it is improbable this species can be found on ships. P. crassa is commonly recorded in the Atlantic, especially in the northeastern part, where there have been a large number of dredgings. It is found on deep-sea crabs, especially on Chaceon affinis. This species occurs in the active vent field, very near mytilid mussels beds (Biscoito & Saldanha 2000, as Poecillasma [sic] cf. kaempferi [Darwin]). In the Pacific, Hoek (1907 a: 12) described P. obliqua from the Moluccas area, a species related to P. crassa, especially in the external characters of the plates. Both species have asymmetrical convex valves, with the scutum having a longitudinal groove, keeled carina and reduced terga. The appendages are also very similar: mandible with four equal teeth, with a denticulate lower margin, lower angle produced, with several setae; maxilla I with the upper angle with strong spines followed by a notch and the lower portion produced and covered by several setae; maxilla II quadrangular, with few setae. But, in P. obliqua Hoek, 1907 the scutum has an internal triangular tooth on the basal part of the occludent margin; the carina is internally convex, with a little fork basally and the cirri of both sides are unequal, the right side smaller. These characters justify the maintenance of P. obliqua as a valid species. P. obliqua was recorded from the Malayan Archipelago and Japan between 204 - 304 m on Macrocheira kaempferi (De Haan) as noted by Zevina (1982: 96).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA3CFF4AFA64FB03FBC3.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 216, 31 ° 53.72 ’ N, 28 ° 02.97 ’ W, 270 m to 31 ° 53.92 ’ N, 28 ° 02.94 ’ W, 270 m, 6 specimens, tl (cl) 3.7 (2.8) to 8.4 (7.1) mm (MNHN Ci 2835, MNRJ 13891). — Stn DW 222, 32 ° 20.81 ’ N, 28 ° 15.66 ’ W, 1150 m to 32 ° 21.02 ’ N, 28 ° 15.72 ’ W, 1150 m, 56 specimens, tl (cl) few to 6.6 (5.3) mm (MNHN Ci 2836, MNRJ 13892). — Stn DW 249, 33 ° 12.41 ’ N, 29 ° 14.83 ’ W, 1700 m to 33 ° 12.36 ’ N, 29 ° 15.19 ’ W, 1800 m, 1 specimen, tl (cl) 11.6 (10.9) mm (MNHN Ci 2837). — Stn DW 250, 33 ° 12.65 ’ N, 29 ° 17.25 ’ W, 1500 m to 33 ° 12.66 ’ N, 29 ° 17.66 ’ W, 1450 m, 7 specimens, tl (cl) 1.6 (1.5) to 7.5 (6.9) mm (MNHN Ci 2838, MNRJ 13893). — Stn TS 267, 34 ° 22.50 ’ N, 30 ° 22.50 ’ W, 2225 m, 8 specimens, tl (cl) 6.6 (5.5) to 20.1 (17.8) mm (MNHN Ci 2839, MNRJ 13894). — Stn DW 276, 34 ° 02.06 ’ N, 28 ° 18.96 ’ W, 1520 m to 34 ° 01.85 ’ N, 28 ° 19.15 ’ W, 1460 m, 5 specimens, tl (cl) 3.4 (3.0) to 10.6 (9.2) mm (MNHN Ci 2840).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA3CFF4AFA64FB03FBC3.taxon	description	DIVA II, stn PL 09, 37 ° 16.32 ’ N, 32 ° 16.51 ’ W, Tour Eiffel, 1685 m, 9 specimens, tl (cl) 6.1 (4.8) to 23.5 (18.6) mm (MNHN Ci 2841, MNRJ 13895). MARVEL, stn PL 1199, Famous, 36 ° 32.26 ’ N, 33 ° 27.40 ’ W, 2364 m,> 40 specimens, tl (cl) few to 20.0 (15.5) mm (MNHN Ci 2884).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA3CFF4AFA64FB03FBC3.taxon	discussion	REMARKS See discussion under G. carinatum below.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA3CFF64FD98FEDAFA23.taxon	description	DIVA II, stn PL 12, 37 ° 50.54 ’ N, 31 ° 31.30 ’ W, Mid- Atlantic Ridge, Menez Gwen, 850 m, 3 specimens, tl (cl) 7.9 (6.3) to 14.2 (11.3) mm (MNHN Ci 2833). MARVEL, stn PL 1201, 37 ° 50.54 ’ N, 31 ° 31.22 ’ W, Menez Gwen, 850 m, 2 specimens, tl (cl) 7.0 (5.7) to 10.9 (7.6) mm (MNHN Ci 2834).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA3CFF64FD98FEDAFA23.taxon	discussion	REMARKS Poecilasma aurantia was first described from Madeira, and recorded elsewhere from the eastern Atlantic. Young (1998 a: 5, b: 33) considered this species distinct from P. kaempferi which is known to occur in the western Pacific region. The validity of the species of Poecilasma has yet to be reevaluated.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA21FC81FB01FCA2F923.taxon	description	(Figs 10 C, D; 12)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA21FC81FB01FCA2F923.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn TS 267, 34 ° 22.50 ’ N, 30 ° 22.50 ’ W, 2225 m, 1 specimen, tl (cl) 21.2 (20.1) mm (MNHN Ci 2842).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324922FA21FC81FB01FCA2F923.taxon	discussion	REMARKS Comparing the description of G. carinatum with that of G. hamatum (Calman 1918 a, 1919), I list some differences in the external characters of the capitular plates as follows. G. hamatum has a scutum with the basal margin straight and forming a right or obtuse angle with the occludent margin whereas G. carinatum has its basal margin form- ing an even curve with the occludent margin. But the specimens of G. carinatum figured by Hoek (1907 a) show the basal margin as described for G. hamatum by Calman (1919). Hoek’s figure from specimens taken by the Challenger Expedition (Hoek 1883) also has a straight basal margin forming an angle with the occludent margin. Calman (1918 a) observed a well-marked umboapical ridge, curved and distant from the occludent margin for G. carinatum and in 1919 he observed a submarginal umbo-carinal ridge, straight or curved for G. hamatum. He noted a relation between the carinal and occludent margins of tergum of one-third to half for G. hamatum and only half for G. carinatum. Nilsson-Cantell (1928: fig. 11) figured a specimen of G. hamatum with a conspicuous apicobasal ridge and an angle between the occludent and basal margins of the scutum. Young (1999: 612) also observed an apicobasal ridge on the scutum of G. carinatum which was collected off the Brazilian coast. Dissecting all the Glyptelasma sampled I found a large number of G. hamatum but only one specimen of G. carinatum. I tried to observe the external characters of these two species to evaluate the differences cited by Calman (1918 a, 1919) and others. All the specimens have an angle between the basal and occludent margins of the scutum (Fig. 10 A, C). The scutum of G. carinatum did not have an apico-basal ridge, but rather a wellmarked lateral (Fig. 10 A, C). Therefore the development of an apicobasal ridge on the scutum is variable in both species. The relationship of half between the carinal and occludent margins of the tergum of G. carinatum may change if more specimens are examined. I cannot observe any external character which could be used to separate these species. Certainly, the best character to separate both species is the number of filamentary appendages on the dorsal margin of the prosoma: G. carinatum has two rows of numerous fine and long filamentary appendages and G. hamatum has only two short projections, which Calman (1919: 372) named dorsal hooks (Fig. 10 B, D). G. carinatum and G. hamatum were collected at the same station on the axes of gorgonians. The general distribution of both species of Glyptelasma are similar: mainly North Atlantic and Indo- Malayan. Glyptelasma hamatum is also found from East Africa, south to Australia and New Zealand (Fig. 11) and G. carinatum from the South Atlantic, Japan and near the Galapagos Island (Fig. 12).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA20FED3FBB9FC07FE43.taxon	description	(Fig. 13 D) MATERIALEXAMINED. — SEAMOUNT 2, stn CP 268, 34 ° 22.03 ’ N, 30 ° 23.14 ’ W, 2205 m to 34 ° 20.54 ’ N, 30 ° 25.00 ’ W, 2145 m, 1 specimen, tl (cl) 20.0 (14.1) mm (MNHN Ci 2844).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA20FED3FBB9FC07FE43.taxon	discussion	REMARKS The single full grown specimen, which at first view, I thought may be D. thieli. But some characters in the shape of the capitulum and reduction of its plates show it is probably a distinct species. The capitulum is short, with its height less than two times its width and with a strongly curved carinal margin. The carina is strongly curved without a basal flattened projection. The scutum has an L-shape with a very thin and long basal arm and an occludent arm which enlarges apically. The peduncle is short and robust. It is difficult to trace a reduction of the plates of D. thieli to attain the scutum and carina form observed in this specimen. Otherwise the proportion of the capitulum and peduncle is very different from the D. thieli. All of the other species of Dichelaspis are very distinct from this specimen. Because there is only one specimen I prefer to maintain the identification as Dichelaspis sp., until more samples become available.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA20FF7DFF78FE4EFC40.taxon	description	(Fig. 13 A-C)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA20FF7DFF78FE4EFC40.taxon	discussion	REMARKS The present specimens have a scutum less reduced than those described in the original description (Young 1998 a: 8); the basal arm is shorter and the occludent arm is still calcified. The terga do not develop an undulated basal margin, which was also observed in a smaller specimen described previously. But all three of the present specimens have the capitulum with a typical triangular shape and the height 2.5 times its width. The differences in the calcification of the plates are considered different stages of development. Dichelaspis thieli was recorded from off Morocco from 1300 m. These new records extend its distribution to the Azores region and to depth between 1300 and 2225 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA20FCA0FDEBFBC0FB23.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA26FD6DFAA0FB6FF923.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 225, 32 ° 08.59 ’ N, 28 ° 10.73 ’ W, 1030 m to 32 ° 08.92 ’ N, 28 ° 10.50 ’ W, 1035 m, 1 specimen, tl (cl) 9.0 (6.2) mm (MNHN Ci 2847). — Stn DW 256, 34 ° 06.21 ’ N, 30 ° 16.03 ’ W, 340 m to 34 ° 06.47 ’ N, 30 ° 16.21 ’ W, 345 m, 2 specimens, tl (cl) 5.2 (3.5) to 8.9 (6.2) mm (MNHN Ci 2848, MNRJ 13897). — Stn CP 257, 34 ° 04.51 ’ N, 30 ° 15.05 ’ W, 338 m to 34 ° 03.21 ’ N, 30 ° 14.25 ’ W, 330 m, 2 specimens, tl (cl) 9.9 (6.9) to 13.2 (9.3) mm (MNHN Ci 2846, MNRJ 13898).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493EFA26FD6DFAA0FB6FF923.taxon	discussion	REMARKS The specimens ranged from 5 to 13 mm in length and the presence of males varied between the specimens. The smallest one did not have a male, probably because this specimen had not yet developed the space between the rostrum and subrostrum where the male cyprids attach nor- mally. The larger specimens had one or two males in the rostral position, but one of them did not have a male. I infer the life time of the males is significatively less than the females, therefore, the females acquire several male cyprids during their life. The relative proportions of the capitulum of Aurivillialepas bocquetae change during growth. The smaller specimens are more slender with the height about twice the width, changing to about 1.5 times in the grown specimens. Aurivillialepas bocquetae was recorded only from off France, between 44 ° - 48 ° N and 7 ° - 8 ° W and from 340 to 519 m (Newman 1980). These new records extend its distribution to the Azores region.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF4CFF40FD24FC20.taxon	description	(Fig. 15)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF4CFF40FD24FC20.taxon	materials_examined	MATERIALEXAMINED. — EQUAMARGE 2, stn DR 08, 3 ° 30 ’ N, 2 ° 40 ’ E, 2420 m, 1 specimen (MNHN Ci 2849).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF4CFF40FD24FC20.taxon	discussion	REMARKS The single specimen collected was badly preserved and all of its plates were disarticulated. Aurivillius (1898) and Gruvel (1920) recorded Scillaelepas grimaldi from the Azores region between 845 - 1230 m. Hiro (1932) considered S. superbum (Pilsbry, 1907) a junior synonym of S. grimaldi which was accepted by Zevina (1981). But, Newman (1980), in his revision of Scillaelepas did not recognize this synonymy. The new record of this species from the Gulf of Guinea extends southward its distribution and its depth to 2420 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF7EFC7DFBC2FB83.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 180, 30 ° 04.09 ’ N, 28 ° 45.09 ’ W, 1575 m to 30 ° 03.90 ’ N, 28 ° 44.74 ’ W, 1610 m, 9 specimens, tl (cl) 1.8 (1.4) to 10.4 (7.4) mm (MNHN Ci 2850, MNRJ 13899). — Stn DW 222, 32 ° 20.81 ’ N, 28 ° 15.66 ’ W, 1150 m to 32 ° 21.02 ’ N, 28 ° 15.72 ’ W, 1150 m, 1 specimen, tl (cl) 1.5 (1.1) mm (MNHN Ci 2851). — Stn DW 249, 33 ° 12.41 ’ N, 29 ° 14.83 ’ W, 1700 m to 33 ° 12.36 ’ N, 29 ° 15.19 ’ W, 1800 m, 3 specimens, tl (cl) 6.9 (5.1) to 10.9 (7.4) mm (MNHN Ci 2852, MNRJ 13900). — Stn DW 261, 34 ° 22.37 ’ N, 30 ° 27.79 ’ W, 1340 m to 34 ° 22.52 ’ N, 30 ° 27.99 ’ W, 1190 m, 1 specimen, tl (cl) 10.9 (8.0) mm (MNHN Ci 2853). — Stn DW 276, 34 ° 02.06 ’ N, 28 ° 18.96 ’ W, 1520 m to 34 ° 01.85 ’ N, 28 ° 19.15 ’ W, 1460 m, 2 specimens, tl (cl) 13.5 (9.2) to 13.6 (9.7) mm (MNHN Ci 2854, MNRJ 13901). — Stn DW 278, 33 ° 57.77 ’ N, 28 ° 22.40 ’ W, 890 m to 33 ° 57.47 ’ N, 28 ° 22.48 ’ W, 925 m, 1 specimen, tl (cl) 11.7 (8.3) mm (MNHN Ci 2855).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF7EFC7DFBC2FB83.taxon	description	40 ° 20 ° 0 ° 40 ° 20 ° 0 ° 20 °	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA25FF7EFC7DFBC2FB83.taxon	discussion	REMARKS Smilium acutum purportedly has a worldwide distribution occurring between 61 and 2480 m. It is commonly collected in the northeastern Atlantic (Hoek 1883; Calman 1918 a; Gruvel 1920; Foster & Buckeridge 1995; Young 1998 b).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA24FD7BFB5AFD1DFF63.taxon	discussion	REMARKS Scalpellum scalpellum is a common species of the northeastern Atlantic occurring in shallow waters of Europe and North Africa (Nilsson-Cantell 1978: 16).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493BFA24FD7BFB5AFD1DFF63.taxon	description	Subfamily MEROSCALPELLINAE Zevina, 1978	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA24FF4EFE9EFE6BF923.taxon	description	BENGAL 3, stn 13200 # 70, 48 ° 51.62 ’ N, 16 ° 31.80 ’ W, 4845 m to 48 ° 50.09 ’ N, 16 ° 33.98 ’ W, 4848 m, 2 specimens, tl (cl) 42.5 (31.0) to 43.8 (31.3) mm (MNHN Ci 2859, MNRJ 13904). — Stn 13200 # 93, 48 ° 50.55 ’ N, 16 ° 25.30 ’ W, 4844 m to 48 ° 47.46 ’ N, 16 ° 30.42 ’ W, 4849 m, 2 specimens, tl (cl) 41.6 (31.6) to 44.4 (29.2) mm (MNHN Ci 2860, MNRJ 13905). — Stn 13200 # 94, 48 ° 50.99 ’ N, 16 ° 23.03 ’ W, 4847 m to 48 ° 47.29 ’ N, 16 ° 32.23 ’ W, 4851 m, 3 specimens, tl (cl) 21.5 (16.6) to 44.7 (31.6) mm (MNHN Ci 2861, MNRJ 13906). BENGAL 5, stn 13368 # 47, 48 ° 51.63 ’ N, 16 ° 25.18 ’ W to 48 ° 50.93 ’ N, 16 ° 25.99 ’ W, 4844 m, 2 specimens, tl (cl) 39.4 (28.9) to 41.8 (29.0) mm (MNHN Ci 2862, MNRJ 13907). — Stn 13368 # 48, 48 ° 49.64 ’ N, 16 ° 30.12 ’ W, 4841 m to 48 ° 45.78 ’ N, 16 ° 32.37 ’ W, 4845 m, 1 specimen, tl (cl) 37.8 (31.6) mm (MNHN Ci 2863). — Stn 13368 # 53, 48 ° 50 ’ N, 16 ° 23.53 ’ W, 4842 m, 9 specimens, tl (cl) 16.7 (13.3) to 49.8 (32.8) mm (MNHN Ci 2864, MNRJ 13908). BENGAL 6, stn 13627 # 11, 48 ° 47.82 ’ N, 16 ° 44.37 ’ W, 4840 m, 4 specimens, tl (cl) 26.4 (20.8) to 42.9 (32.4) mm (MNHN Ci 2865, MNRJ 13909). — Stn 13627 # 24, 48 ° 50.47 ’ N, 16 ° 44.37 ’ W, 4840 m, 2 specimens, tl (cl) 42.4 (30.4) to 46.9 (30.5) mm (MNHN Ci 2866, MNRJ 13910).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA24FF4EFE9EFE6BF923.taxon	discussion	REMARKS The present samples contain only full grown specimens of Neoscalpellum debile. This species has been commonly dredged on both sides of the North Atlantic between 2321 and 5318 m (Gruvel 1920; Pilsbry 1907 a as Scalpellum dicheloplax; Newman & Ross 1971; Young 1998 a, b). It was also recorded in the South Atlantic: off Tristan da Cunha, Angola, and Brazil (Foster & Buckeridge 1995 as Meroscalpellum bifurcatum [Zevina, 1973] [Young 1999]).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	description	(Figs 16; 17)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	materials_examined	TYPE MATERIAL. — Holotype 1, N. Ireland, PROS- PEC, stn CPH 10, 55 ° 18.69 ’ N, 10 ° 14.83 ’ W, 1589 m to 55 ° 18.11 ’ N, 10 ° 15.38 ’ W, 1578 m, 1600 m, tl (cl) 43.1 (26.6) mm (MNHN Ci 2867); paratypes, same locality, 6 specimens, tl (cl) 29.9 (18.9) to 49.4 (27.8) mm (MNHN Ci 2868, MNRJ 13911).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	etymology	ETYMOLOGY. — Named in honor of my friend and spiritual mentor Arnold Ross.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	diagnosis	DIAGNOSIS. — Scutum with lateral arm less than onethird length of tergal margin. Upper-latus pentagonal with subapical umbo. Inframedian-latus vase shaped, with umbo almost basal. Caudal appendage with five articles, length nearly equal to protopodite.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	description	DESCRIPTION Capitulum (Fig. 16 A) oval, flattened, length less than twice width; growth lines thin and inconspicuous. Cuticle reddish, thick, sparsely pilose and with well-marked sutural plate scars. Tergum (Fig. 16 A) divided into two arms, with original surface area larger than that of scutum. Basal margin with deep concavity. Carinal margin slightly concave with lateral thickening near apex of carina. Occludent margin straight turning strongly convex in apical portion. Apex curved toward carina. Scutum (Fig. 16 A) convex, with short lateral arm, length less than one-third length of tergal margin; height more than twice greatest width. Basal margin slightly convex. Tergal margin nearly straight. Occludent margin convex. Apex not overlying on tergum. Carina (Fig. 16 A, B) regularly arched, with umbo situated at three-quarters of length. Tectum flat; lateral angulary bent; basal margin straight. Upper-latus (Fig. 16 A) nearly pentagonal with umbo subapical, slightly projecting above surface of capitulum. Tergal and scutal margins symmetrical, slightly concave; other margins having an irregular outline. Carino-latus (Fig. 16 A, B) higher than wide, with umbo basal, slightly projecting outward. Lateral margin having an irregular outline. Carino-latera not in contact with one another. C Inframedian-latus (Fig. 16 A) vase shaped with umbo almost basal; umbo projecting outwards. Rostro-latus (Fig. 16 A, C) wider than high, width almost four times height, without apicobasal ridge. Upper margin slightly concave; lateral margin rounded. Rostrum (Fig. 16 C) absent. Peduncle (Fig. 16 A) little shorter than capitulum, covered sparsely by scales deeply immersed in cuticle. Scale whorl eight-plate pattern: rl-cl, sr-l-sc. Labrum (Fig. 17 A) bullate, without teeth. Palp (Fig. 17 A, B) elongated with several fine setae on apex and few small setae on inner margin. Mandible (Fig. 17 C) with three teeth; lower angle denticulate, without setae. Maxilla I (Fig. 17 D) small, with straight anterior border, and 11 large and smaller and unpaired spines. Maxilla II (Fig. 17 E) squared; covered with numerous large and simple setae except for medi- an space on anterior margin and another on upper margin; papilla of maxillary gland pronounced. Cirrus I (Fig. 17 F) with anterior ramus twothirds length of posterior ramus; former with protuberant articles; both rami covered by numerous large, simple setae. Cirrus II to VI with equal rami. Median article of cirrus VI (Fig. 17 G) almost two times longer than wide, four groups of setae on anterior margin, upper one with four setae, uniformly distributed small setae on lateral surface, scales and intercalated setae on posterior margin and three setae on posterior angle. Caudal appendage (Fig. 17 H) with five articles, nearly same length as protopodite of cirrus VI; articles with few, small setae on anterior margins, and cluster of pinnate setae on apex. Number of articles of cirri I-VI and caudal appendage is presented in Table 4.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32493AFA29FCB8FF48FDE7F920.taxon	discussion	REMARKS Barbascalpellum rossi n. sp. is the first species of this genus recorded from the Atlantic Ocean. The genus is represented in the Pacific Ocean by B. sanctabarbarae (Pilsbry, 1907) from California and by B. cochlearium (Hiro, 1933) from Japan. B. rossi n. sp. is very distinct from B. cochlearium and can be distinguished by the latter having the upper-latus with a distinct shape and a fringed basal margin, the tergum with thinner branches, the carina with the roof bordered by prominent ridges, and the carino-latus with a concavity. On the other hand, B. sanctabarbarae is very similar to B. rossi n. sp. but the former has the capitulum with a strongly convex occludent margin, the rostro-latus is very low, and it has a rostrum. Barbascalpellum rossi n. sp. is known only from the type locality, N. Ireland, from 1600 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324937FA28FD4AFDD5FCC4FAC3.taxon	description	(Fig. 18)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324937FA28FD4AFDD5FCC4FAC3.taxon	materials_examined	MATERIALEXAMINED. — PROSPEC, stn CPH 10, 55 ° 18.69 ’ N, 10 ° 14.83 ’ W, 1589 m to 55 ° 18.11 ’ N, 10 ° 15.38 ’ W, 1578 m, 3 specimens, tl (cl) 29.5 (19.7) to 49.0 (33.4) mm (MNHN Ci 2869, MNRJ 13912). SAINT PAUL, stn SP 09 - 13, 01 ° 00.73 ’ N, 29 ° 21.61 ’ W, 3114 m, 1 specimen, tl (cl) 15.5 (12.2) mm (MNHN Ci 2870).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324937FA28FD4AFDD5FCC4FAC3.taxon	discussion	REMARKS Arcoscalpellum michelottianum is probably a complex of several distinct species (Ross in litt. 1999). He noted conspicuous differences between specimens of Hoek’s types series of Scalpellum velutinum Hoek, 1883, photographed by Young (1998 a: fig. 13 a-d). The specimens differ in the relative development of the upper-latus, the position of the apex of the carina relative to the apex of the scutum and in the number and size of the plates on the peduncle. The specimens herein studied comprises the “ Arcoscalpellum velutinum ” type of Hoek, shown in Young (1998 a: fig. 13 c-d). A question about the peduncular pattern is if there are any changes in this pattern during the development? The three specimens record- ed have distinct sizes (tl of 29.5, 37.5 and 49.0 mm). If all the scales of the specimens are figured some differences can be observed. In the smaller stage the peduncular plate pattern is the basic eight-plate pattern with one row of rl-cl and another of sr-l-sc (Fig. 18 A). The large specimen has a six-plated pattern lacking the cl plates (Fig. 18 C). In the intermediate size individual, there is a change in the pattern from eight-plates to large plates in a six-plate pattern also with the exclusion of the cls (Fig. 18 B). During ontogeny, the narrow basal part of the peduncle has irregularly spaced plates, which obscures the original pattern. On the other hand, this observation reaffirms the supposition of an eight-plate pattern as a simplesiomorphic character in scalpellids (Newman & Ross 1998).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324936FA12FCBAFA35FDF5F920.taxon	description	(Figs 19 - 22)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324936FA12FCBAFA35FDF5F920.taxon	description	DESCRIPTION Capitulum (Fig. 19 A) oval, flattened, length almost twice width, occludent and carinal margins convex and similar. Plates with strong radial ribs, except on carinal part of tergum; with spaced, thin growth lines. Cuticle thin, not pilose. Tergum (Fig. 19 A) with its surface area greater than scutum; inconspicuous apicobasal ridge. Basal margin straight. Carinal margin slightly convex, with lateral thickening near apex of carina. Occludent margin convex. Apex slightly curved toward carina. Scutum (Fig. 19 A) with conspicuous apicobasal ridge, separating two surfaces; height more than twice greatest width. Basal margin straight. Tergal margin slightly concave, presenting a lid. Occludent margin nearly straight, only distally convex. Lateral margin convex except for upper concavity to accept apex of upper-latus. Apex curved, superimposed on tergum. Carina (Fig. 19 A, B) arching more conspicuously at apex, wider at upper portion, with umbo slightly subapical. Tectum flat, bordered by lateral ridges; basal margin nearly straight. Upper-latus (Fig. 19 A) pentagonal with apex curved toward scutum, umbo subapical, projecting. Scutal margin concave; other margins straight. Carino-latus (Fig. 19 A, B) nearly pentagonal, higher than wide, with umbo at carinal base, not projecting backward. Carino-latera interdigitating with one another below carina. Inframedian-latus (Fig. 19 A) triangular, with umbo curved toward scutum, with two apical wings projecting toward carinal margin. Rostro-latus (Fig. 19 A, C) trapezoidal, wider than high, width almost two times height, with an apico-basal ridge. Lower margin two-thirds length of upper margin. Rostrum (Fig. 19 C) small, reduced to narrow slip between rostro-latera. Peduncle (Fig. 19 A) one-third length of capitulum, covered by large scales projecting outward. Scale whorl eight-plate pattern: rl-cl; sr-l-sc. Labrum (Fig. 20 A) bullate, with series of about 47 denticles. Palp (Fig. 20 A, B) short, acuminate with few simple setae. Mandible (Fig. 20 C, D) with three teeth or with second and third reduced; lower angle denticulate. Maxilla I (Fig. 20 E) with anterior border having medial notch, and two large and 10 smaller unpaired spines. Maxilla II (Fig. 20 F) rounded, globose; covered by numerous simple setae; papilla of maxillary gland pronounced. Cirrus I (Fig. 21 A) with unequal rami, anterior ramus three-quarter length of posterior ramus; former with protuberant articles. Cirrus II with equal rami but shorter than posterior cirri. Cirri III to VI with equal, long rami. Cirri I to III with several long, simple setae on anterior margin, lateral face and posterior margin, which decreases progressively in size and number toward posterior rami (Fig. 21 B-D). Larger setae of median article of cirri II, III and IV, 2.5, 3.3, 1.8 times length of article, respectively (Fig. 21 B-D). Median article of cirrus VI less than two times longer than wide, three pairs of simple setae unequal in length and few fine setulae on anterior margin; unpaired simple setae on lateral face; intercalated setae on posterior margin and one or two setae on posterior angle. Number of articles of cirri I-VI and caudal appendage is presented in Table 5. Caudal appendage (Fig. 21 E), with six to seven articles, shorter than length of coxopodite of cirrus VI; articles with few, small setae on distal margins, one or two long setae on anterior margin, and cluster of simple setae on apex. Penis absent.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324936FA12FCBAFA35FDF5F920.taxon	discussion	REMARKS Gruvel (1920) considered Scalpellum semisculptum Pilsbry, 1907 to be synonymous with Arcoscalpellum mamillatum n. comb. This synonymy was considered doubtful by Broch (1953: 7) and Nilsson-Cantell (1955: 218) but accepted by Zevina (1981: 269) in her revision of the scalpellid. This species is transferred to Amigdoscalpellum because the apex of the inframedian-latus does not reach the upper margin of the lower row of plates. Herein the synonymy between these species is not considered and both species are placed in different genera: Amigdoscalpellum semisculptum and Arcoscalpellum mamillatum n. comb. The latter species has a large inframedian-latus, with its apex reaching the upper margin of the rostro- and carino-latus. Table 6 presents the differences between both species justifying their separation. 60 ° 40 ° 20 ° 80 ° 60 ° 40 ° 20 ° 0 ° The distribution of Arcoscalpellum mamillatum n. comb. is therefore restricted by the original samples (Azores region) and the new record (Bay of Biscay). Amigdoscalpellum semisculptum is recorded from the Gulf of Mexico and west of Iceland (Fig. 22) (Broch [1953] cited Scalpellum semisculptum as collected at stn 10 but when he figured it on map 12 he marked in the stn 25, I considered the citation of stn 10 [West of Iceland] as the correct one). Arcoscalpellum atlanticum (Gruvel, 1900) n. comb. (Figs 23; 24)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324936FA12FCBAFA35FDF5F920.taxon	discussion	REMARKS The specimens examined (Fig. 23) agree with the description of Gruvel (1902 d: 74) including the general eight-plate pattern of the peduncle. I only observed a variation in the roof of the carina. It C varied from flat with conspicuous high bordering ribs in smaller specimens to flat with very low inconspicuous bordering ribs in larger ones. The specimens I identified as Arcoscalpellum tritonis (Hoek, 1883) from Portugal, Morocco and Azores should be placed in A. atlanticum (Gruvel, 1900) n. comb. (Young 1998 a: 19, b: 36). I originally tought A. tritonis may be a junior synonym but a few character differences and its geographic distribution (Fig. 24) suggests maintaining both species as valid. A. tritonis has the rostro-latus more trapezoidal, and the inframedian-latus with a curved apex, more scales on the peduncle and it does not have a rostrum.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490CFA11FC8DFA9AFE71FC63.taxon	discussion	REMARKS Only one small specimen with broken plates was collected during the MARVEL Expedition. It does not have the longitudinal ridges fully developed, especially on the tergum and scutum. When reviewing the literature, I noted that different stages of peduncular development were figured by different authors (Sars 1885; Broch 1924, 1953; Stephensen 1936; Tarasov & Zevina 1957; Nilsson- Cantell 1978). Their small specimens had an eightplate pattern of scales in two whorls (rl-cl and sr-l-sc) which is transformed in larger specimens to two whorls of approximately four to five similar plates. Verum striolatum is a common species from the Arctic Ocean ranging between 62 ° N and 80 ° N, and between 342 and 2700 m (Zevina 1981: 222). This new sample extends significantly its distribution to the Azores region.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA11FF3CFBD5FBE2FB20.taxon	description	(Fig. 25)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA11FF3CFBD5FBE2FB20.taxon	materials_examined	MATERIALEXAMINED. — ECOFER 1, stn CP 01, 44 ° 46.20 ’ N, 02 ° 38.15 ’ W, 3017 m, 1 specimen, tl (cl) 17.7 (13.8) mm (MNHN Ci 2877). — Stn CP 02, 44 ° 46.14 ’ N, 02 ° 38.92 ’ W, 3033 m, 1 specimen, tl (cl) 26.4 (20.2) mm (MNRJ 13915).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA11FF3CFBD5FBE2FB20.taxon	discussion	REMARKS The specimens have a more inflated capitulum in the region of the base of the scutum instead of having a uniform breadth as observed by Young (1998 b: 40). The rostro-latus is as high as wide in	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA11FF3CFBD5FBE2FB20.taxon	description	60 ° 40 ° 20 ° 0 ° 80 ° 60 ° 40 ° 20 ° 0 ° 20 ° smaller specimens (Fig. 25 A) and higher than wide in larger specimen (Fig. 25 B) and the rostrum is not visible between the rostro-latera. The specimens are larger than that observed by Young (1998 b). The strength of the longitudinal ridges of capitular plates varies among the specimens, the smaller had them more pronounced than the larger one.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA11FF3CFBD5FBE2FB20.taxon	discussion	Catherinum recurvitergum has been recorded from the Azores region (type locality) and eastern Africa (Gruvel 1900 a: 190; Weltner 1922: 72). The new records extend its septentrional distribution from the Bay of Biscay, France.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA10FD5DFB6CFCCFF923.taxon	description	(Fig. 26)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA10FD5DFB6CFCCFF923.taxon	materials_examined	MATERIALEXAMINED. — BENGAL 2, stn 13078 # 27, 48 ° 50.13 ’ N, 16 ° 39.86 ’ W to 48 ° 59.06 ’ N, 16 ° 38.58 ’ W, 4844 m, 1 specimen, tl (cl) 38.8 (29.8) mm (MNRJ 13916). — SEAMOUNT 2, stn CP 236, 32 ° 03.72 ’ N, 27 ° 40.59 ’ W, 1925 m to 32 ° 05.52 ’ N, 27 ° 39.69 ’ W, 1960 m, 1 specimen, tl (cl) 21.6 (17.0) mm (MNHN Ci 2878).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490FFA10FD5DFB6CFCCFF923.taxon	discussion	REMARKS The specimen collected at station 13078 is exceptionally large (38.8 mm) and probably represents the greatest length this species attains. The plates appear to be old with a considerable amount of erosion. It is interesting to note how reduced the inframedian-latus is in this specimen, when compared with younger ones (Fig. 26). The inframedian-latus seems to lose its function of covering the suture between the lower latera and becomes an eroded small plate situated over the rostrolatus. Amigdoscalpellum rigidum is a common deepsea pedunculate occurring between 1267 and 4810 m from the Azores, Cape Verde, Iberian, West European and Newfoundland basins (Aurivillius 1898; Gruvel 1905; Young 1998 a, b).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA17FF43FB1EFD52FD5B.taxon	discussion	REMARKS The taxonomic status of Trianguloscalpellum ovale was recently reviewed (Young 1998 a: 32). This species is frequently recorded from the abyssal plain of the North Atlantic. A C	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA17FE8FFF78FF7AFBE3.taxon	description	BENGAL 3, stn 13200 # 93, 48 ° 50.55 ’ N, 16 ° 25.30 ’ W, 4844 m to 48 ° 47.46 ’ N, 16 ° 30.42 ’ W, 4849 m, 1 specimen, tl (cl) 71 mm (MNRJ 13917). BENGAL 6, stn 13627 # 11, 48 ° 47.82 ’ N, 16 ° 40.37 ’ W, 4847 m, 2 specimens, tl (cl) 27.0 (20.7) to 27.9 (20.8) mm (MNHN Ci 2880, MNRJ 13878).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA17FE8FFF78FF7AFBE3.taxon	discussion	REMARKS The taxonomy of Trianguloscalpellum regium was recently reviewed (Young 1998 a: 28). This species has been reported from all the oceans, but probably this distribution encompasses more than one species (Young 1998 a). It is frequently recorded from the abyssal plain of the North Atlantic.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA16FCA6FA64FBF6FB40.taxon	description	(Fig. 27)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA16FCA6FA64FBF6FB40.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 278, 33 ° 57.77 ’ N, 28 ° 22.40 ’ W, 890 m to 33 ° 57.47 ’ N, 28 ° 22.48 ’ W, 925 m, 1 specimen, rc 2.9 mm (MNRJ 13920). MARVEL, stn PL 1196, Mid-Atlantic Ridge, Rainbow vent site, 36 ° 13.78 ’ N, 33 ° 54.14 ’ W, 2295 m, 2 specimens, rc 2.8 mm (MNHN Ci 2882).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324909FA16FCA6FA64FBF6FB40.taxon	discussion	REMARKS Altiverruca erecta was redescribed and discussed by Young (1998 c: 111). The specimens collected during the present expeditions are similar to that figured by Gruvel (1902 d: pl. 5, figs 7, 8) and indicate the growth ridges are more prominent on the carina (Fig. 27). It was collected from the Azores at 3175 m and from the Mid-Atlantic Ridge between 3947 and 3375 m (Gruvel 1902 d: 93; Young 1998 c: 111). These new records agree with the previous geographic distribution but increase its depth range to 890 - 3947 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324908FA15FC9BFA8AFE5FFDE0.taxon	description	(Fig. 28)	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324908FA15FC9BFA8AFE5FFDE0.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 186, 31 ° 26.14 ’ N, 28 ° 51.77 ’ W, 1520 m to 31 ° 26.34 ’ N, 28 ° 51.93 ’ W, 1520 m, 1 empty shell, rc 3.2 mm (MNHN Ci 2883). — Stn DW 277, 33 ° 59.92 ’ N, 28 ° 20.56 ’ W, 1000 m to 33 ° 59.64 ’ N, 28 ° 20.81 ’ W, 945 m, 1 specimen, rc 4.5 mm (MNRJ 13921).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324908FA15FC9BFA8AFE5FFDE0.taxon	discussion	REMARKS The specimens from both stations have shells similar to that described by Hoek (1883: 143) with the carina very convex (Fig. 28). Altiverruca obliqua was redescribed and discussed by Young (1998 b: 46). It was first described from off Southwestern Spain (Hoek 1883) and subsequently recorded from the Azores region (Young 1998 b, c) from depths between 1003 to 2788 m. These new records agree with the previous distribution. They were collected south of the Azores Archipelago at depths of 945 and 1000 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490BFA14FF46FDE1FF7AF923.taxon	description	MARVEL, stn PL 1196, Mid-Atlantic Ridge, Rainbow vent site, 36 ° 13.78 ’ N, 33 ° 54.14 ’ W, 2295 m, 2 specimens, rc 3.9 to 4.7 mm (MNHN Ci 2889, MNRJ 13926).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490BFA14FF46FDE1FF7AF923.taxon	discussion	REMARKS The present specimens (Fig. 29) agree with the original description of A. quadrangularis. The complete specimen figured by Hoek (1883: pl. 12, fig. 8) differs from the details of the opercular valves shown in his pl. 12, figs 11, 12. In his fig. 12, the tergum has a flat surface between the tergal margin and it has longitudinal ridges, which are missing from the specimen in his fig. 8. My specimens have this area well-developed (Fig. 29 A, C). Otherwise, the medial ridge of the tergum is more pronounced in his fig. 11 when compared with his fig. 8. This ridge is barely distinguished in the present specimens. The specimens exhibit variable development of the carinal apex. Sometimes it projects (Fig. 29 C, D), and is reminiscent of the carinal apex of Altiverruca longicarinata (Gruvel, 1900). However, this latter species has a distinct rostrum and carina, both with a flat surface near the opercular margins.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490AFA1BFD68FAA7FE70FE40.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 209, 31 ° 59.17 N, 27 ° 55.95 W, 460 m to 31 ° 58.93 N, 27 ° 56.19 W, 435 m, 1 specimen, rc 3.5 mm (MNHN Ci 2905). — Stn DW 231, 32 ° 01.49 ’ N, 27 ° 54.51 ’ W, 745 m to 32 ° 01.75 ’ N, 27 ° 54.70 ’ W, 750 m, 1 specimen, rc 10.3 mm (MNRJ 13927). — Stn DW 247, 33 ° 13.69 ’ N, 9 ° 35.26 ’ W, 580 m to 33 ° 13.69 ’ N, 29 ° 35.54 ’ W, 625 m, 1 specimen, rc 3.9 mm (MNHN Ci 2907).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A32490AFA1BFD68FAA7FE70FE40.taxon	discussion	REMARKS Costatoverruca cornuta was redescribed and discussed by Young (1998 a: 42). The geographic record and depth were given previously: Azores region between 450 and 1229 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324905FA1BFF43FDD8FE55FB00.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324905FA1BFF51FB5AFB54FB03.taxon	discussion	REMARKS Metaverruca recta was collected from ahermatypic corals and sponges. This species is possibly the most commonly dredged deep-sea verrucid. It has a circumtropical and temperate distribution but is unknown from the western coast of the Americas.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324905FA1AFC82FB5AFD8FFEE0.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324904FA1AFC94FDF5FCD7F923.taxon	materials_examined	MATERIALEXAMINED. — SEAMOUNT 2, stn DW 148, 30 ° 12.01 ’ N, 28 ° 24.64 ’ W, 615 m to 30 ° 11.94 ’ N, 28 ° 24.60 ’ W, 585 m, 12 eroded disarticulated plates (MNHN Ci 2912). — Stn DW 221, 32 ° 17.84 ’ N, 28 ° 15.32 ’ W, 1180 m to 32 ° 18.03 ’ N, 28 ° 15.47 ’ W, 1160 m, 6 disarticulated plates (MNHN Ci 2913). — Stn DW 243, 33 ° 13.18 ’ N, 29 ° 08.24 ’ W, 1420 m to 33 ° 13.47 ’ N, 29 ° 07.85 ’ W, 1360 m, 38 disarticulated plates (MNHN Ci 2914). — Stn DW 264, 34 ° 24.74 ’ N, 30 ° 30.77 ’ W, 830 m to 34 ° 24.85 ’ N, 30 ° 31.08 ’ W, 795 m, 1 disarticulated plate (MNHN Ci 2915). — Stn DW 283, 43 ° 34.51 ’ N, 22 ° 19.61 ’ W, 1175 m to 43 ° 34.32 ’ N, 22 ° 19.43 ’ W, 1210 m, 7 eroded disarticulated plates (MNHN Ci 2916). PROSPEC, stn CPH 4, 56 ° 32.53 ’ N, 10 ° 17.03 ’ W to 56 ° 32.75 ’ N, 10 ° 15.39 ’ W, 1185 m, 4 specimens, rc 13.3 - 13.5 mm (MNHN Ci 2917, MNRJ 13937).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324904FA1AFC94FDF5FCD7F923.taxon	discussion	REMARKS All the samples consisted of disarticulated erod- ed plates except those from station CPH 4. The identification was based on comparison between solid plated balanomorphs from this region and depth: Pachylasma giganteum, Bathylasma hirsutum and Hexelasma americanum. In the southern area of the Azores, Bathylasma hirsutum was recorded by Young (1998 b: 66).	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324904FA1AFF5DFAE0FB9EFEE3.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324904FA1AFF4DFDB5FDD8FB63.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324907FA18FF55FA9FFDBCFCE0.taxon	discussion	REMARKS Most of the specimens have the carinal plate significantly higher than the other plates (Fig. 30 A, B). The outline of the terga varied with the spur varying from distally rounded to a more square termination (Fig. 30 C-E). Hexelasma americanum was described from the western Atlantic by Pilsbry (1916: 330) based on specimens taken on the Blake Plateau, Florida. It was also recorded from the Mid-Atlantic Ridge and Azores region (Young 1998 b: 66, c: 117). The new samples, consisting a large number of specimens, suggest that H. americanum is a common species on the eastern Atlantic seamounts, between 715 and 1420 m.	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
03927A324906FA18FF65FBA3FF66F923.taxon	discussion	REMARKS	en	Young, Paulo S. (2001): Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions. Zoosystema 23 (4): 705-756, DOI: http://doi.org/10.5281/zenodo.4689055
