taxonID	type	description	language	source
D317A101FFE2AD695BC0FDAAFC66FB82.taxon	type_taxon	Type species. Paxillus adversa H. Adams & A. Adams, 1851, by typification of replaced name.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD695BC0FDAAFC66FB82.taxon	discussion	Remarks. This genus was synonymized with Diplommatina W. H. Benson, 1849 by Vermeulen (1993), a view that has been accepted by subsequent researchers (Maassen 2001, Marzuki et al. 2021). However, recent molecular phylogenies continue to support the monophyly of Gastroptychia (Webster et al. 2012, Boonmachai et al. 2023, Köhler 2023). Currently, the morphological diagnostic characters of Gastroptychia cannot be clearly summarized because the generic concept and its species are intermixed with those of Diplommatina, necessitating a thorough revision. We include the new species and those sinistral species listed below in the Gastroptychia primarily to avoid turning Diplommatina into a wastebasket genus. In the future, these species may be reassigned to new generic taxa as the diagnostic characteristics of Gastroptychia are more clearly defined.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	description	(Figure 1)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	materials_examined	Type specimens. Holotype: NHMUK 20240383 / 1 (1 specimen), labels: Shillong, Khasi, low ground [on the box]; Shillong Station, low ground [in the vial]. [current geopolitical location: Shillong, East Khasi Hills, Meghalaya, India]. H. H. Godwin-Austen Collection. Paratypes: NHMUK 20240383 / 2 - 11 (10 specimens, one was broken for study, as NHMUK 20240383 / 2), same data as holotype.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	etymology	Etymology. This name comes from the Latin word collis (hill) with the suffix - cola (dweller), as the type locality is famous for its rolling hills.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	diagnosis	Diagnosis. Gastroptychia collicola sp. nov. is characterized by the ovately fusiform shell and widely spaced ribs, with a palatal swelling situated on ventrolateral side of the body whorl, a strong horizontal palatal lamella presents just after and a strong and twisted columellar lamella.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	description	Description. Shell small, sinistral, pale with brown hue, ovately fusiform, with 5.25 convex whorls; suture impressed; apex blunt; penultimate whorl widest; lateral side of the body whorl very flattened in aperture view. Protoconch consisting of 1.25 whorls, somewhat matte with very fine radial threads; boundary between protoconch and teleoconch clear. Teleoconch surface with fine and regularly arranged radial and prosocline ribs, approximately 9 ribs on the penultimate whorl when view from the aperture side, very weak and dense spiral threads situated only on the lower part of the body whorl. A palatal swelling situated on ventrolateral side of the body whorl, attached to the aperture. Aperture oval, vertical. Peristome double, spaced, upper part largely attached to the body whorl, nearly reaching the penultimate whorl, but with margin distinctly detached; outer peristome expanded, at the same height as inner peristome, with an inconspicuous curved columellar lip, visible from aperture view; inner peristome expanded but not reflected. Internal constriction distinctly presents ventrally with a thin basal radial (to the shell axis) palatal fold. A small parietal lamella presents near the constriction. A strong horizontal palatal lamella presents just anterior to the swelling, situated from lateral side to dorsal side. Columellar lamella large, oblique, interior part distanced with constriction; columellar tooth emerged from aperture, downward sloping. Umbilicus closed. Operculum corneous, thin, translucent, light amber coloured; nucleus not observed. Measurements. Shell height: 1.98 mm, shell width: 1.20 mm, aperture height: 0.91 mm, aperture width: 0.81 mm (holotype).	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	diagnosis	Differential diagnosis. The palatal swelling of the new species cannot be found in all the other Gastroptychia. This new species resembles sympatric species Gastroptychia gibberosa (Godwin-Austen, 1892), Gastroptychia gibbosa (W. T. Blanford, 1868) and Gastroptychia jaintiaca (Godwin-Austen, 1870) from Meghalaya and Manipur, India in general shell shape. The new species is distinguished from latters by its smaller shell size (shell height: 2 mm vs 2.5 – 3.2 mm), the distinctive palatal swelling and palatal lamella. Gastroptychia formosana (Pilsbry & Hirase, 1906) from Taiwan Island is also similar to the newly described species. However, aside from the absence of palatal swelling and lamellae, the former species has sparser ribs.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	discussion	Remarks. The type specimens in lot NHMUK 20240383 were separated from a mixed lot registered as NHMUK 1903.7.1.3597 from the Godwin-Austen collection, containing 25 dextral specimens and provisionally labelled with a note from Godwin-Austen that reads “ D. nr sherfaiensis ” which we assume stands for near Diplommatina sherfaiensis Godwin-Austen, 1870.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE2AD6B5BC0F90AFB16FBE5.taxon	distribution	Distribution. INDIA: Meghalaya. The new species is known only from the type locality.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	description	(Figure 2)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	materials_examined	Type specimens. Holotype: NHMUK 20240334 / 1, label: 34. Diplommatina n. sp. (sinistral), 10. Darjeeling, Dr F. Stoliczka; 35. Diplommatina n. sp. 2. Darjeeling, n. sp. [current geopolitical location: Darjeeling, West Bengal, India]. ex. Indian Museum Collection. Paratypes: NHMUK 20240334 / 2 - 10 (9 specimens), same data as holotype.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	etymology	Etymology. This new species is named after Geoffrey Nevill (1843 – 1885), who first recognised this species as new to science.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	diagnosis	Diagnosis. Gastroptychia geoffreyi sp. nov. is characterized by the ovately fusiform shell, with convex body whorl, dense ribs on the teleoconch surface and a columellar tooth weakly emerged from aperture.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	description	Description. Shell small, sinistral, light brown, ovately fusiform, with 4.5 – 4.75 convex whorls; suture impressed; apex blunt; body whorl at same width as penultimate whorl. Protoconch consisting of 1.25 – 1.5 whorls, somewhat matte; boundary between protoconch and teleoconch clear. Teleoconch surface with fine and regularly arranged radial and prosocline ribs, approximately 7 ribs per 500 μm on the body whorl, very weak and dense spiral threads situated, distinct on the body whorl. Aperture oval, slightly oblique to the shell axis. Peristome double, spaced, attached to the body whorl; callus thin or slightly thickened; outer peristome expanded, at the same height as inner peristome; inner peristome expanded but not reflected, central part of the palatal margin slightly to significantly curved inward. Internal constriction presents ventrally with a thin basal radial (to the shell axis) palatal fold. Other internal structure unknown, no horizontal palatal lamella observed through translucent shell. Columellar tooth weakly emerged from aperture. Umbilicus closed. Operculum unknown. Measurements. Shell height: 2.48 – 2.53 mm, shell width: 1.46 – 1.50 mm, aperture height: 0.98 – 1.03 mm, aperture width: 1.01 – 1.06 mm (n = 2).	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	diagnosis	Differential diagnosis. The new species, from the foothills of the eastern Himalayas, is distinct from species from the Shillong Plateau, i. e. Gastroptychia collicola sp. nov., Gastroptychia gibberosa (Godwin-Austen, 1892), Gastroptychia gibbosa (W. T. Blanford, 1868) and Gastroptychia jaintiaca (Godwin-Austen, 1870), by the dense ribs on the surface of the shell, lateral side of the body whorl very convex in aperture view and the small columellar tooth. Gastroptychia geoffreyi sp. nov. also somewhat resembles Diplommatina sulcicollis Möllendorff, 1897 and Diplommatina javana Möllendorff, 1897 from Java and Bali in general shape, and both of which also have small columellar tooth present (Nurinsiyah & Hausdorf 2017, Vermeulen & Whitten, 1998). The new species differs from latters by its spaced double peristomes and relatively strong ribs.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE0AD6D5BC0FBDFFB05FE24.taxon	distribution	Distribution. INDIA: West Bengal. The new species is known only from the type locality.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FD9FFD97FC1F.taxon	description	(Figure 3 B)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FD9FFD97FC1F.taxon	materials_examined	Type material. Syntypes NHMUK 1903.7.1.2240 (22 specimens). Type locality. “ South of the Barak River between Munipur and Imphal ”	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FD9FFD97FC1F.taxon	distribution	Distribution. INDIA: Manipur.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FB81FD19F974.taxon	description	(Figure 3 A)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FB81FD19F974.taxon	materials_examined	Type material. Syntypes NHMUK 1906.5.5.39 (5 specimens). Type locality. “ Habiang in montibus Garo ”	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6D5BC0FB81FD19F974.taxon	distribution	Distribution. INDIA: Meghalaya, Assam.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6F5BC0F96FFD19FF0D.taxon	description	(Figure 3 C)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6F5BC0F96FFD19FF0D.taxon	materials_examined	Type material. Syntypes NHMUK 1903.7.1.2243 (24 specimens). Type locality. “ Locally plentiful in damp woods near Jawai, Jaintia hills, at about 4500 ft. elevation ”	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE6AD6F5BC0F96FFD19FF0D.taxon	distribution	Distribution. INDIA: Meghalaya, Assam.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE4AD6F5BC0FE82FD19FC2E.taxon	description	(Figure 4)	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE4AD6F5BC0FE82FD19FC2E.taxon	materials_examined	Type material. Syntypes NHMUK 1903.7.1.2250 (15 specimens). Type locality. “ In the forests of Burrail range, at about 3000 feet, Asalu, particularly the forest near Garilo or Chota Asalu ”	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
D317A101FFE4AD6F5BC0FE82FD19FC2E.taxon	distribution	Distribution. INDIA: Meghalaya, Assam.	en	Chen, Zhe-Yu, Ablett, Jonathan D. (2024): Two new Gastroptychia Kobelt & Möllendorff, 1900 from Darjeeling and West Khasi Hills, northeastern India (Gastropoda: Cyclophoroidea: Diplommatinidae). Zootaxa 5538 (1): 79-88, DOI: 10.11646/zootaxa.5538.1.8, URL: https://doi.org/10.11646/zootaxa.5538.1.8
