taxonID	type	description	language	source
D42D87DB6B27FFB6FF72FD702602999A.taxon	description	Figure 2	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B27FFB6FF72FD702602999A.taxon	materials_examined	Examined material (25 specimens). LACM 84 - 7, 24 specimens (4 under SEM), coral heads and sand, Pigeon Id, off Nilaveli, Sri Lanka, 8 ° 43.5 ’ N, 81 ° 12.2 ’ E, intertidal to 2 m, leg. James H. McLean, Edith Abbott, Joan Sherman, 17 March 1984; FMNH 339458, 1 specimen, same collection data as LACM 84 - 7. Type locality. Baros Island, North Malé Atoll, Republic of Maldives.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B27FFB6FF72FD702602999A.taxon	diagnosis	Diagnosis. Ammonicera with two spiral rows of nodules on the body whorl; periphery keeled.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B27FFB6FF72FD702602999A.taxon	description	Description. Shell planispiral, tightly coiled. Shell wall thick, opaque, glossy, dark amber in coloration. Protoconch 1 (P 1) of c. 1.1 whorls (diameter 86 µ m in Figure 2 B), sculptured with 1 raised nodule at mid-whorl and reticulate sculpture peripheral to nodule, occupying a broad groove on both the apical and basal surfaces. Boundary to protoconch 2 conspicuous to poorly marked. Protoconch 2 (P 2) of c. 0.65 whorls (diameter 151 µ m in Figure 2 B, including P 1), sculptured with c. 5 nodules at mid-whorl and reticulate sculpture peripheral to nodules on both the apical and basal surfaces; P 2 nodules becoming axially elongated and reticulate sculpture fading out towards the boundary with the teleoconch. Boundary between protoconch and teleoconch conspicuous to poorly marked. Teleoconch of c. 1.6 whorls; first 1 / 4 whorl sculptured by axially elongated nodules extending from midwhorl to the outer suture on the apical and basal surfaces; subsequently with 2 spiral rows of nodules, 1 adjacent to the inner and 1 to the outer suture on both the apical and basal surfaces. Nodules of the outer row larger than those of the inner row and linked by a spiral cord from the second 1 / 2 whorl of the teleoconch onwards. Secondary spiral sculpture of the teleoconch composed of numerous very fine lirae, with interspaces approximately matching their width, overlaying the outer rows of nodules and the shell periphery. Body whorl with c. 14 – 17 nodules on each spiral row; periphery marked by a raised spiral cord; supraperipheral and infraperipheral walls straight to gently concave, with or without an axial sculpture of narrow and low riblets; inner lip broadly concave, flaring slightly. Aperture sub-quadrate. Shell dimensions (in mm) and whorl counts:	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B27FFB6FF72FD702602999A.taxon	discussion	Remarks. This is the first record of this species outside of its type locality in Baros Island, Maldives (Sleurs, 1985 b). We based the description above solely on the examined Sri Lankan material, which matches the original description and illustrations of this species very well. A minor but noteworthy difference is the less pronounced secondary spiral ornamentation in our specimens, which appear to lack spiral lirae altogether on the inner row of nodules (compare Figure 2 herein with fig. 4 in Sleurs, 1985 b).	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B27FFB6FF72FEF024279C06.taxon	diagnosis	Diagnosis. Shell extremely minute; protoconch with conspicuous ridges and / or grooves; sculpture of the teleoconch usually prominent, seldom weak; aperture rounded to subquadrate; radular rows composed of two bent, dagger-like teeth, articulating at their outer side with a very small marginal tooth [formula 1 - 1 - 0 - 1 - 1]; cephalic tentacles cylindrical.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B26FFB1FF73F93827F99BE7.taxon	description	Figure 3	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B26FFB1FF73F93827F99BE7.taxon	materials_examined	Examined material (12 specimens). LACM 79 - 58, 11 specimens (4 under SEM, one previously lightphotographed), rocky substrate, Long Reef, Sydney, New South Wales, Australia, 33 ° 44.5 ’ S, 151 ° 19.2 ’ E, intertidal, leg. James H. McLean, 13 May 1979; FMNH 339459, 1 specimen, same collection data as LACM 79 - 58. Type locality. North Harbour, New South Wales, Australia.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B26FFB1FF73F93827F99BE7.taxon	diagnosis	Diagnosis. Ammonicera with a conspicuous spiral groove and a faint spiral cord on the protoconch; teleoconch sculptured by weak axial ribs and by a spiral sculpture of broad, elongated pits interspersed with raised nodules; spiral sculpture fading out on the body whorl.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B26FFB1FF73F93827F99BE7.taxon	description	Description. Shell planispiral, tightly coiled. Shell wall very thin, pellucid, glossy, amber in coloration. Protoconch of c. 1.2 whorls, finely pitted, sculptured on its apical and basal surfaces by a faint spiral cord midwhorl and a broad spiral groove positioned equidistantly between the cord and the outer suture. Boundary between P 1 and P 2 poorly marked to indistinct; boundary between protoconch and teleoconch marked by interruption of the spiral grooves and onset of the axial sculpture of the teleoconch. Teleoconch of c. 2 whorls, with an axial sculpture of weak ribs; spiral groove of the protoconch replaced on the first 1.5 whorls of the teleoconch by a primary spiral sculpture of broad, elongated pits interspersed with raised nodules, the latter positioned at intersections with the axial ribs; primary spiral sculpture fading out on the last 1 / 2 whorl of the teleoconch. Secondary spiral sculpture of the teleoconch composed of numerous very fine lirae, with interspaces approximately matching their width, occurring on both apical and basal surfaces from mid-whorl to the shell periphery. Shell periphery transitioning from obtusely angled along the first 1.5 whorls of the teleoconch to uniformly rounded subsequently. Apical and umbilical sutures impressed; outer lip sharply convex in the vicinity of the sutures, straight to broadly convex along apical and basal walls, uniformly rounded along periphery; inner lip concave, flaring slightly. Aperture subcrescent. Shell dimensions (in mm) and whorl counts:	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B26FFB1FF73F93827F99BE7.taxon	discussion	Remarks. The original description and illustrations of Helisalia sucina by Laseron (1954), who tentatively assigned this species to the family Liotiidae Gray, 1850, were based on light microscopy alone and are insufficiently detailed. Ponder & de Keyzer (1998) recognised this species as a member of Ammonicera and published the first SEM image of the shell in apical view, as well as a sketch of the live animal. The redescription presented herein is based on SEM micrographs of shells collected c. 10 km north of the type locality. A. sucina shares with A. plicata Sleurs, 1985 b, which is only known from its type locality in the Maldives, a similar sculptural pattern, but differs from the latter species in several aspects: (1) the shell periphery is obtusely angled in A. sucina, rather than uniformly rounded (compare Figure 3 E – F herein with fig. 7 in Sleurs, 1985 b); (2) apical and basal walls are flattened in A. sucina, whereas they are uniformly rounded in A. plicata; (3) A. sucina has a shallower apical suture; and (4) the spiral sculpture of the teleoconch fades out sooner in A. plicata (approximately from the beginning of the third shell whorl) than it does in A. sucina (from the second half of the third shell whorl). A further related look-alike is the Atlantic A. lineofuscata Rolán, 1992 b, which is readily distinguished from A. sucina by a more pronounced sculpture (see Rolán, 1992 b, figs 22, 24, 25), and a colour pattern of three spiral brown bands (see Tunnell et al., 2010, p. 258).	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	description	Figure 4	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	materials_examined	Examined material (92 specimens). Holotype: LACM 3288 (SEM), flood control channel, Mission Bay, San Diego Co., U. S. A., 32 ° 45.5 ’ N, 117 ° 15.0 ’ W, 5 - 8 ft [1.5 – 2.4 m], leg. James H. McLean & Patrick LaFollette, 15 August and 11 October 1971. Paratypes (3): LACM 3289 (Paratypes 1, 3; SEM, Paratype 3 previously lightphotographed), from the holotype lot; FMNH 339460 (Paratype 2; SEM), from the holotype lot. Additional material: LACM 71 - 101, 9 specimens from the type locality. LACM 71 - 83, 6 specimens (SEM), Los Arcos, Banderas Bay, Jalisco, West coast of Mexico, 20 ° 32 ’ N, 105 ° 19 ’ W, intertidal to 15 ft [4.6 m], leg. James H. McLean & Jeff Margetts, 30 May to 1 June 1971; LACM 68 - 41, 1 specimen (SEM), south side of Bahia Cuastocomate (3 air miles NW of Barra de Navidad), Jalisco, Mexico, 19 ° 13 ’ 45 ” N, 104 ° 44 ’ 53 ” W, 15 – 65 ft [4.6 – 19.8 m], leg. James H. McLean & Peter Oringer, 13 – 21 October 1968; LACM 71 - 14, 66 specimens, east side of Punta Entrada at Sail Rock (north entrance to Magdalena Bay), Baja California, Mexico (24 ° 32.4 ’ N, 112 ° 04 ’ W, 10 – 50 ft [3 – 15.2 m], leg. James H. McLean, 30 – 31 January 1971; LACM 66 - 12, 1 specimen, Cape San Lucas, Baja California, Mexico (22 ° 8 ’ N, 110 ° W, 25 – 100 ft [7.6 – 30.5 m], leg. James H. McLean & Peter Oringer, 3 – 4 April 1966; LACM 71 - 183, 5 specimens, Man of War Cove, Magdalena Bay, Baja California, Mexico (24 ° 37.5 ’ N, 112 ° 7.5 ’ W, intertidal to 35 ft [10.7 m], leg. James H. McLean & Patrick LaFollette, 31 October 1971.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	diagnosis	Diagnosis. Ammonicera with a broad spiral cord ornamenting the protoconch and teleoconch, gradually fading out on the body whorl; shell diameter c. 0.6 – 0.7 mm at 3 whorls.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	description	Description. Shell planispiral, tightly coiled. Shell wall very thin, pellucid, glossy, fawn in coloration. Protoconch of c. 1.4 whorls, sculptured with 1 broad spiral cord on its apical and 1 broad spiral cord on its basal surface; spiral cords closer to the outer than to the inner suture. Basal surface of the protoconch finely pitted. Protoconch 2 stage absent; boundary between protoconch and teleoconch conspicuous to poorly marked. Teleoconch of c. 1.8 whorls, with a primary spiral sculpture composed of 5 broad cords separated by 4 marked grooves; the 2 most central cords (1 apical and 1 basal) continuous with those of the protoconch; 1 additional cord positioned at the shell periphery and 2 cords (1 apical and 1 basal) subperipherally; grooves between cords c. 0.1 - 0.75 the width of the central cords. Secondary spiral sculpture of the teleoconch composed of numerous very fine lirae, with interspaces approximately matching their width, overlaying the primary spiral sculpture. Spiral sculpture gradually fading out in the last 1 / 2 whorl of the teleoconch. Axial sculpture of the teleoconch composed of growth lines only, which become crowded in the last 1 / 4 whorl of the teleoconch. Apical and umbilical sutures impressed; outer lip sharply convex in the vicinity of the sutures, uniformly rounded along the apical, peripheral and basal walls; inner lip broadly concave, flaring slightly. Aperture and operculum rounded. Shell dimensions (in mm) and whorl counts:	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	discussion	Remarks. A. sleursi is remarkably similar to A. lignea Palazzi, 1988, an Eastern Atlantic species endemic to the Madeira Archipelago. They share weak axial sculpture and broad spiral ribs that fade out towards the aperture. However, the shell of A. sleursi is considerably smaller than that of A. lignea at the same whorl count. The holotype and paratype of A. lignea illustrated by Palazzi (1988, figs 8,18) measure c. 0.92 mm at 3.24 whorls, and 0.82 mm at 3.13 whorls, respectively [our measurements], and Segers et al. (2009, p. 488) illustrated a specimen of A. lignea measuring 0.8 mm at c. 2.94 whorls. In contrast, the largest known shell of A. sleursi is the holotype, which measures 0.70 mm at 3.21 whorls. Obviously, the geographic separation of A. sleursi and A. lignea is also relevant in recognising them as separate species. A. sleursi is also similar to the Western Atlantic A. circumcirra Rolán, 1992 b, recorded from Cuba (the type locality; see Rolán, 1992 b) and from the Saint Peter and Saint Paul Archipelago, Brazil (Lima et al., 2011). However, the sculpture of A. circumcirra is more prominent than that of A. sleursi, particularly in the presence of weak elevations formed by the intersection of axial ribs with spiral cords. Additionally, the sculpture of A. circumcirra appears to be persistent, rather than fading along the teleoconch (Rolán, 1992 b, fig. 23; Lima et al., 2011, fig. 5). Mediterranean A. fischeriana Monterosato, 1869 differs from A. sleursi in displaying a colour pattern of three spiral brown bands and in having a more pronounced axial sculpture.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B20FFB3FF72F9D3203298AA.taxon	etymology	Etymology. This species is dedicated to Dr. Willy J. M. Sleurs, Research Associate of the Royal Belgian Institute of Natural Sciences, in recognition of his contribution to our knowledge of Indo-Pacific omalogyrids.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B22FFBDFF72F8FE24939816.taxon	description	Figure 5	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B22FFBDFF72F8FE24939816.taxon	materials_examined	Examined material (19 specimens). Holotype: LACM 3284 (SEM, color photograph before SEM), W side of Cerralvo Is., Baja California, Mexico, 24 ° 10 ’ N, 109 ° 52 ’ W, 30 – 50 ft [9.1 – 15.2 m], leg. James H. McLean, 3 February 1971. Paratypes (3): LACM 3285 (Paratypes 1, 2; SEM), from the holotype lot; FMNH 339461	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B22FFBDFF72F8FE24939816.taxon	discussion	Remarks. The shells of Ammonicera mcleani and A. mexicana sp. nov. (described below) resemble those of Atlantic A. sculpturata Rolán, 1992 b and Papua New Guinean A. nodicarinata (Sleurs, 1985 c) in the presence of two spiral cords delimiting the peripheral wall and a single row of nodules on the apical and basal surfaces of the shell. They differ from both of these previously described species in bearing smaller and more numerous nodules on the body whorl (10 – 15 in A. nodicarinata; c. 12 in A. sculpturata). They additionally differ from A. sculpturata in having a less rounded aperture, and from A. nodicarinata in the later ontogenetic onset of their nodules (see Rolán, 1992 b; Sleurs, 1985 c). The shape of the periphery is the most obvious criterion to distinguish A. mcleani and A. mexicana. It is broadly convex in the former species, whereas in the latter a prominent spiral cord divides the peripheral wall in two concave sectors. Additional distinguishing features are the more discoidal shape of A. mexicana and the slightly more prominent nodules of A. mcleani.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B22FFBDFF72F8FE24939816.taxon	etymology	Etymology. This species is dedicated to Dr. James McLean, Curator Emeritus at LACM and renowned specialist of the eastern Pacific gastropod fauna, who personally collected and encouraged us to study the material reported upon in this paper.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	description	Figure 6	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	materials_examined	Examined material (24 specimens). Holotype: LACM 3286 (SEM, color photograph before SEM), south side of Bahia Cuastocomate (3 air miles NW of Barra de Navidad), Jalisco, Mexico, 19 ° 13 ’ 45 ” N, 104 ° 44 ’ 53 ” W, 15 – 65 ft [4.6 – 19.8 m], leg. James H. McLean & Peter Oringer, 13 – 21 October 1968. Paratypes (3): LACM 3287 (Paratypes 1, 2; SEM), from the holotype lot; FMNH 339462 (Paratype 3; SEM), from the holotype lot. Additional material: LACM 68 - 41, 7 specimens from type locality; LACM 71 - 83, 9 specimens, Los Arcos, Banderas Bay, Jalisco, West coast of Mexico, 20 ° 32 ’ N, 105 ° 19 ’ W, intertidal to 15 ft [4.6 m], leg. James H. McLean & Jeff Margetts, 30 May to 1 June 1971; LACM 65 – 28, 1 specimen, Barra de Navidad, Jalisco, West coast of Mexico, 19 ° 20 ’ N, 105 ° W, 5 – 20 ft [1.5 – 6.1 m], leg. Nick Furjanick, 26 June 1965; LACM 67 - 9, 1 specimen, Isla Isabela, 45 miles northwest of San Blas, Nayarit, West coast of Mexico, 21 ° 51 ’ N, 105 ° 55 ’ W, 30 ft [9.1 m], leg. Chuck Snell & Bob McMillen, 11 February 1967; LACM 67 - 155, 2 specimens, Isla Roqueta, Acapulco de Juaréz, Guerrero, West coast of Mexico, 16 ° 49 ’ N, 99 ° 56 ’ W, 15 – 20 ft [4.5 – 6.1 m], leg. Twila Bratcher, 10 May 1967.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	diagnosis	Diagnosis. Ammonicera with spiral cords delimiting a keeled peripheral wall; additionally sculptured by a single row of 14 – 20 nodules each on the apical and basal walls of the body whorl.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	description	Description. Shell planispiral, tightly coiled. Shell wall very thin, pellucid, glossy, amber in coloration. Protoconch of c. 1.4 whorls, with the first whorl sculptured on its apical and basal surfaces by 3 spiral cords; inner spiral cord positioned approximately mid-whorl, broad, prominent; central and outer spiral cords approximately equidistantly distributed between the inner cord and the outer suture; central cord c. 1 / 4 the width and height of the inner cord; outer cord c. 1 / 2 the width and equivalent in height to the central cord; surface of the protoconch finely pitted between inner suture and inner spiral cord, and with a reticulate sculpture between inner spiral cord and outer suture; sculpture of the protoconch transitioning to large nodules positioned mid-whorl along approximately the last 1 / 2 whorl. Protoconch 2 stage absent; boundary between protoconch and teleoconch poorly marked. Teleoconch of c. 1.4 whorls, sculptured by 1 broad and prominent spiral cord at the shell periphery and on both the apical and basal surfaces by 1 similar spiral cord each at the junction with the peripheral wall; apical and basal surfaces additionally sculptured by 1 spiral row of axially elongated nodules, positioned in the inner half of each whorl, with interspaces c. 1 – 3 times their width, gradually increasing in height throughout the teleoconch; body whorl with 14 – 20 nodules; secondary sculpture of the teleoconch composed of very fine and somewhat wavy spiral grooves. Apical and umbilical sutures shallowly impressed; outer lip convex in the vicinity of the sutures, straight along each of 4 segments between obtuse vertices corresponding to the 3 continuous spiral cords and 2 nodulose spiral cords of the teleoconch; inner lip concave, not flaring. Aperture almost hexagonal. Shell dimensions (in mm) and whorl counts:	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	discussion	Remarks. Ammonicera mexicana appears to be closely related to A. mcleani, from which it differs in having a keeled periphery, a more discoidal shape and slightly less prominent nodules. Criteria to distinguish Ammonicera mexicana from seemingly more distantly related look-alikes were discussed under the remarks for A. mcleani.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2CFFBFFF72F96126779B09.taxon	etymology	Etymology. Mexicanus-a-um, adjective; from Mexico.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B2EFFBFFF72FA4124649972.taxon	diagnosis	Diagnosis. Shell extremely minute; protoconch smooth or finely nodulose, devoid of conspicuous axial or spiral sculpture; sculpture of the teleoconch weak or absent; aperture rounded; each radular row composed of a single dagger-like tooth, flanked by one lateral plate on each side [formula 0 - (1) - 1 - (1) - 0]; cephalic tentacles forming rounded lobes.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B29FFB8FF72FF45259099DE.taxon	description	Figures 1, 7	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B29FFB8FF72FF45259099DE.taxon	materials_examined	Examined material (10 specimens). LACM 79 - 58, 9 specimens (5 SEM, 1 previously light-photographed), rocky substrate, Long Reef, Sydney, New South Wales, Australia, 33 ° 44.5 ’ S, 151 ° 19.2 ’ E, intertidal; leg. James H. McLean, 13 May 1979; FMNH 339463, 1 specimen, same collection data as LACM 79 - 58. Type locality. Castle Rock, Middle Harbour, Port Jackson, New South Wales	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B29FFB8FF72FF45259099DE.taxon	diagnosis	Diagnosis. Omalogyra of uniform coloration, sculptured by faint axial ribs and fine growth lines; inner lip concave, aperture sub-crescent; shell diameter c. 0.6 mm at 2 1 / 2 whorls.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B29FFB8FF72FF45259099DE.taxon	description	Description. Shell planispiral, tightly coiled. Shell wall very thin, pellucid, glossy, amber in coloration. Protoconch of c. 1.2 whorls, much lighter than the teleoconch in coloration, sculptured only by microscopic, irregular nodules on the nuclear shell, gradually fading out toward the boundary with the teleoconch. Protoconch 2 poorly marked or absent; boundary between protoconch and teleoconch very well marked. Teleoconch of c. 1.2 whorls, sculptured by faint, irregularly spaced axial ribs, and by fine growth lines; shell devoid of spiral ornamentation. Apical and umbilical sutures deeply impressed; outer lip uniformly rounded; inner lip concave, flaring slightly. Aperture sub-crescent. Shell dimensions (in mm) and whorl counts:	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
D42D87DB6B29FFB8FF72FF45259099DE.taxon	discussion	Remarks. This is the type species of the genus Helisalia Laseron, 1954, by original designation. The original description and illustrations by Laseron (1954), who tentatively assigned Helisalia to the family Liotiidae, were based on light microscopy alone and are insufficiently detailed. Marshall (1988) regarded Helisalia liliputia as possibly belonging to Orbitestellidae Iredale, 1917, whereas Healy (1993) and Ponder & de Keyzer (1998) relocated this species to Omalogyra. Healy (1993) described the sperm ultrastructure of O. liliputia, noting that it shares with O. atomus Philippi, 1841 a glycogen helix and paracrystalline material in the midpiece. Ponder & de Keyzer (1998) published the first SEM image of the shell of O. liliputia in apical view, as well as a diagram of the live animal. Here, we provide a re-description based on SEM micrographs of shells collected c. 10 km north of the type locality. O. liliputia shares a morphologically simple shell, devoid of pronounced sculpture, with several other Omalogyra species, namely O. antarctica Egorova, 1991, O. atomus, O. disculus Palazzi, 1988, O. fuscopardalis Rolán, 1992 b, O. simplex (O. G. Costa, 1861) and O. zebrina Rolán, 1992 b. The uniform coloration of the teleoconch of O. liliputia immediately separates this species from the Atlantic O. zebrina, O. fuscopardalis and Atlantic / Mediterranean O. simplex, all of which display coloration patterns on their teleoconch. O. liliputia differs from Atlantic O. disculus in having a higher, less discoidal shell (compare Figure 7 G herein with fig. 3 in Rolán, 1992 a [reproduced by Rolán, 2005, fig. 842]) and from the northern hemisphere O. atomus in displaying a larger degree of overlap of the body whorl over the previous whorl, which results in a more curved inner lip and less rounded aperture (compare Figure 7 G herein with illustrations of O. atomus in apertural view by Palazzi, 1988, fig. 26, Gaglini, 1993, p. 928 - 04 and Gofas, 2011, p. 357). The circum-antarctic O. antarctica is the only southern hemisphere species of Omalogyra that resembles O. liliputia. However, they differ in a number of aspects (Egorova, 1991; Engl, 2012): (1) O. antarctica reaches 1.4 mm in diameter and is much larger than O. liliputia at the same whorl count; (2) O. antarctica has a proportionally lower aperture, with an outer lip that is flattened apically and basally, whereas in O. liliputia the outer lip is uniformly rounded; and (3) O. antarctica is ornamented only by growth lines, whereas O. liliputia has weak axial ribs.	en	Sartori, André F., Bieler, Rüdiger (2014): Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia). Zootaxa 3872 (1): 1-21, DOI: 10.11646/zootaxa.3872.1.1
