taxonID	type	description	language	source
03B487A07F12FFC2FF301304698DA569.taxon	description	Figures 2 A – B, 3 A, 4 A – D, 6	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	materials_examined	Type Material. Holotype (male): “ BRAZIL: Amazonas: Manaus / - 2.93079, - 59.97514, 75 m / Ducke Reserve, Igarape Barro / Branco; Short & team; forest / pools; 6. vi. 2018; BR 18 - 0606 - 02 C ”, “ [barcode] / SEMC 1623338 / KUNHM-ENT ” (INPA). Paratypes (34): BRAZIL: Amazonas: Same data as holotype (8 exs., INPA, SEMC, including DNA Voucher is SLE 1848); same data but “ forest pools ”, BR 18 - 0606 - 02 A (4 exs., SEMC); same data but stream margin and associated backwater swampy area, 9 – 10. vi. 2018, BR 18 - 0609 - 3 A (2 exs., SEMC). VENEZUELA: Amazonas: Cerro de la Neblina, 1 km S. Basecamp, 17. ii. 1985, leg. Faitoute & Steiner, “ along small whitewater stream, pools of dead leaves and sticks ” (20 exs., USNM, MIZA, SEMC).	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	diagnosis	Differential diagnosis. Chasmogenus clinatus is very similar to a cluster of species that have sinuate parameres and a well-developed accessory sclerite on the median lobe (Fig. 4 A – D). The aedeagus of this species is most similar to that of C. pandus (Fig. 4 F) in that both have a bent medial sclerite that lies dorsally to the median lobe and the outer margins of the parameres have a weak undulating appearance. However, the median lobe of C. clinatus is uniformly wide throughout its length until the apex acuminates past the parameres, whereas the median lobe of C. pandus is wider at the base and gradually acuminates throughout the entire length towards the apex. The outer margins of the parameres of C. clinatus have a single medial constriction (sinuate) between the base and the position of the gonopore and C. pandus has two lateral constrictions (bisinuate), one medial and one closer to the apex of the parameres. The two species may be differentiated by dorsal coloration as well: C. clinatus is dark brown, whereas C. pandus is a slightly paler reddish brown.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	description	Description. Size and color. Total body length 2.9 – 3.6 mm. Body form elongate oval with slightly curved lateral margins. Dorsum of head orange-brown to very dark brown, clypeus and labrum paler brown (Fig. 3 A). Pronotum and elytra uniformly dark orange-brown (Fig. 2 A). Venter uniformly dark orange-brown (Fig. 2 B). Head. Ground punctation on head fine. Clypeus with anteromedial emargination, which exposes a narrow, rounded to angulate gap between the clypeus and labrum (Fig. 3 A). Mentum deeply depressed in anterior two-thirds with a triangular to rounded anteromedial notch. Maxillary palps long, longer than width of head immediately posterior to eyes. Thorax. Ground punctation on pronotum fine (Fig. 2 A). Prosternum very weakly to not at all tectiform. Mesoventrite with moderate elevation forming a thin posteromedial longitudinal carina. Metafemora densely pubescent in basal nine-tenths (Fig. 2 B). Aedeagus. Aedeagus (Fig. 4 A – D) with median lobe nearly parallel-sided and uniformly wide, then tapering gradually to a weakly acuminate apex, distinctly extending beyond the apex of the parameres. Sclerite of the median lobe expanded and developed into a long, narrow sliver, angled slightly to the left with a sharply acute apex that extends to or just beyond the apex of the parameres. Gonopore situated in the middle of the median lobe, ca. two to three gonopore widths below the apex. Parameres symmetrical, outer margins with a single medial constriction, apical half slightly narrower than basal half; apex slightly acuminate. Basal piece short, ca. one-third the length of the parameres.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	etymology	Etymology. The species name is derived from the Latin clinatus meaning “ bent ” or “ sloped ” after the condition of the medial sclerite on the median lobe of the aedeagus.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	distribution	Distribution. This species is known from the Ducke Reserve in Manaus, state of Amazonas, Brazil and from the extreme south of Venezuela at the foot of Cerro de la Neblina.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F12FFC2FF301304698DA569.taxon	biology_ecology	Biology. This species was collected from a series of forest pools and riparian areas in northern Brazil (Amazonas) and along whitewater streams in southern Venezuela.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	description	Figures 2 C – D, 3 B, 5 C – D, 6	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	materials_examined	Type Material. Holotype (male): “ VENEZUELA, T. F. Amaz. / Cerro de la Neblina / 1.5 km S Basecamp / 0 ° 50 ’ N, 66 ° 10 ’ W / 250 m., 15 Feb. 1985 ”, “ In small ponds full / of dead leaves; / rainforest ridge / P. J. & P. M. Spangler, / R. Faitoute, W. Steiner ” (MIZA). Paratypes (36): VENEZUELA: Amazonas: Same data as holotype (36 exs., SEMC, USNM).	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	diagnosis	Differential Diagnosis. Among species with the median lobe of the aedeagus and the parameres approximately even in length and a long basal piece, this species is similar in morphology and general form of the aedeagus to C. brownsbergensis Smith & Short, 2020, but may be distinguished by characters of the median lobe and dorsal coloration of the head. The median lobe of C. gironae bears a rounded triangular apex past the position of the gonopore and a constriction located medially, whereas the apex of C. brownsbergensis is acutely triangular with straight sides and the constriction is situated more distally closer to the gonopore. The coloration of the head of C. brownsbergensis has mesal dark patches on the clypeus and the labrum compared to the uniformly colored head of C. gironae.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	description	Description. Size and color. Total body length 3.4 – 3.7 mm. Body form elongate oval. Dorsum of head dark brown to very dark brown posteriorly, clypeus and labrum slightly paler (Fig. 3 B). Pronotum and elytra uniformly very dark brown (Fig. 2 C). Venter uniformly dark orange-brown to dark brown (Fig. 2 D). Head. Ground punctation on head fine. Clypeus with anteromedial emargination, which exposes a broadly rounded gap between the clypeus and labrum (Fig. 3 B). Mentum moderately depressed in anterior half with a triangular to rounded anteromedial notch. Maxillary palps long, longer than width of head immediately posterior to eyes. Thorax. Ground punctation on pronotum fine (Fig. 2 C). Prosternum very weakly to not at all tectiform. Mesoventrite with moderate elevation forming a thin posteromedial longitudinal carina. Metafemora densely pubescent in basal nine-tenths (Fig. 2 D). Aedeagus. Aedeagus (Fig. 5 C, D) with median lobe that bears a single medial constriction situated halfway between base and apex, base and position of gonopore of equal width, tapering past position of gonopore narrowing abruptly to form a rounded triangular apex which is even with the apex of the parameres. Sclerite of the median lobe not expanded. Gonopore situated ca. half of one gonopore width below the apex of the median lobe. Parameres symmetrical, with outer margins straight, with apex slightly inwardly curved and bluntly rounded. Basal piece long, ca. half the length of the parameres.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	etymology	Etymology. This species is named in honor of Dr. Jennifer Girón, for her substantial contributions and dedication to the study of the taxonomy and morphology of the subfamily Acidocerinae and for her valuable mentorship of the first author.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	distribution	Distribution. Known only from the type locality near the base of Cerro de la Neblina in southern Venezuela.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F16FFC1FF30149F6E65A6A5.taxon	biology_ecology	Biology. Chasmogenus gironae was collected in small ponds full of leaves in lowland rainforest.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	description	Figures 3 C, 5 A – B, 6	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	materials_examined	Type Material. Holotype (male): “ BRAZIL: Amazonas: Manaus / - 2.93079, - 59.97514, 75 m / Ducke Reserve, trail to Igarape / Acara; Short & team; muddy / area with emergent vegetation / 7 – 8. vi. 2018; BR 18 - 0607 - 01 A ”, “ [barcode] / SEMC 1623365 / KUNHM-ENT ” (INPA). Paratypes (7): BRAZIL: Amazonas: Same data as holotype (4 exs., INPA, SEMC); same locality but Flight Intercept Trap (FIT) (2 exs., SEMC, DNA vouchers SLE 1892 and SLE 1894); Novo Airão Municipio, - 2.68396, - 60.93840, Densely vegetated margin of blackwater creek, BR 17 - 0609 - 04 A (1 ex., SEMC, DNA voucher SLE 1267)	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	diagnosis	Differential diagnosis. This species is similar to a group that have an aedeagal form with relatively broad, straight parameres and a wide median lobe which is slightly shorter to slightly longer than the apex of the parameres. It is distinctly smaller in overall size than C. amplius Smith & Short, 2020, C. berbicensis Smith & Short, 2020, and C. clavijoi Smith & Short, 2020. The apex of the parameres curve slightly inward like that of C. schmits Smith & Short, 2020, but are not bluntly squared and the apex of the median lobe distinctly reaches the apex of the parameres or just slightly beyond. It is most similar to the comparably-sized C. guianensis Smith & Short, 2020, but the median lobe is distinctly longer and even with the apex of the parameres.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	description	Description. Size and color. Total body length 3.7 – 3.9 mm. Body form elongate oval with slightly curved lateral margins. Dorsum of head orange brown to dark brown, clypeus and labrum distinctly paler (Fig. 3 C). Pronotum and elytra uniformly orange-brown. Venter uniformly orange-brown to dark orange brown. Head. Ground punctation on head fine. Clypeus with anteromedial emargination, which exposes a broadly rounded gap between the clypeus and labrum (Fig. 3 C). Mentum weakly depressed in anterior third with a triangular to rounded anteromedial notch. Maxillary palps long, longer than width of head immediately posterior to eyes. Thorax. Ground punctation on pronotum fine. Prosternum weakly tectiform. Mesoventrite with moderate elevation forming a thin posteromedial longitudinal carina. Metafemora densely pubescent in basal nine-tenths. Aedeagus. Aedeagus (Fig. 5 A, B) with median lobe widest at base, and slightly tapering gradually until the apical quarter, then narrowing abruptly to form an acute triangular apex which is even with or extends slightly past the apex of the parameres. Sclerite of the median lobe not expanded. Gonopore situated less than half of one gonopore width below the apex of the median lobe. Parameres symmetrical, with outer margins slightly curved inwardly and apex slightly inwardly curved and bluntly rounded. Basal piece of medium to long length, ca. one half to two-thirds the length of the parameres.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	etymology	Etymology. Named after the Instituto Nacional de Pesquisas da Amazônia, an organization dedicated to advancing our understanding of the Amazon, and who also administers the Adolfo Ducke Forest Reserve from where this species was collected.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	distribution	Distribution. This species is known only from the Ducke Reserve in Amazonas State, northern Brazil.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F15FFC0FF3017D36F75A7A7.taxon	biology_ecology	Biology. Collected in muddy vegetated areas along a trail to Igarapé Acará.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F14FFCFFF3016D56EFBA669.taxon	discussion	We have modified the key presented in Smith & Short (2020) to insert the three species described here. All three species would key to couplet 13 in the original key, so we have not repeated those here. We emphasize that examination of the genitalia is crucial to accurate identifications and unassociated females of the three species described here cannot be identified with precision.	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
03B487A07F1BFFCFFF3016296996A7C2.taxon	materials_examined	New material examined (21): BRAZIL: Amapá: Oiapoque, (c. 22 km S on BR- 156), 3.65822 °, - 51.76958 °, 17 m, 20. vii. 2018, leg. Short, forested detrital pool, BR 18 - 0720 - 01 B (9 exs., INPA, SEMC). Pará: Alenquer, Vale do Paraíso, ca. 55 km N of Alenquer, - 1.49292, - 54.51566, 150 m, 3. ii. 2018, leg. A. Short, isolated detrital pool in rocks next to river, BR 18 - 0203 - 01 B (9 exs., INPA, SEMC).	en	Glynn, Rachel D., Short, Andrew Edward Z. (2021): New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae). Zootaxa 5048 (3): 435-443, DOI: https://doi.org/10.11646/zootaxa.5048.3.8
