Endothyrella macromphalus (W. Blanford, 1870)

Pall-Gergely, Barna, Budha, Prem B., Naggs, Fred, Backeljau, Thierry & Asami, Takahiro, 2015, Review of the genus Endothyrella Zilch, 1960 with description of five new species (Gastropoda, Pulmonata, Plectopylidae), ZooKeys 529, pp. 1-70 : 29-30

Taxon classification Animalia Pulmonata Plectopylidae

Endothyrella macromphalus (W. Blanford, 1870) Figures 23 A–B

Endothyrella macromphalus 1870 Helix (Plectopylis) macromphalus W. Blanford: Journal of the Asiatic Society of Bengal, 39 (2): 17-18, Plate 3, fig. 14. ["ad Mairung in montibus Khasi"].

Endothyrella macromphalus 1870-1876 Helix macromphalus , - Hanley & Theobald: Conchologia Indica …: Plate 83, figs 8-10.

Endothyrella macromphalus 1875 Plectopylis macromphalus , - Godwin-Austen: Proceedings of the Zoological Society of London: 612, 613, Plate 73, figs 1, 1a. ["Darjeeling and N. E. frontier, Bengal. Khási”] (1874, part IV, published in 1875; see Duncan 1937).

Endothyrella macromphalus 1878 Helix (Plectopylis) macromphalus , - Nevill: Hand list of Mollusca in the Indian Museum, Calcutta...: 71.

Endothyrella macromphalus 1879b Helix (Plectopylis) macromphalus , - Godwin-Austen: The Annals and Magazine of Natural History, 5 (4): 163-164.

Endothyrella macromphalus 1887 Helix (Plectopylis) macromphalus , - Tryon: Manual of Conchology …, 2 (3): 160, Plate 34, figs 65-68.

Endothyrella macromphalus 1892 Plectopylis macromphalus , - Godwin-Austen: The Annals and Magazine of Natural History, 6 (10): 301.

Endothyrella macromphalus 1893 Plectopylis macromphalus , - Pilsbry: Manual of Conchology..., 2 (8): 297.

Endothyrella macromphalus 1894 Plectopylis macromphalus , - Pilsbry: Manual of Conchology..., 2 (9): 146.

Endothyrella macromphalus 1897c Plectopylis macromphalus , - Gude: Science Gossip, 4: 10-11, figs 46 a–b. ["Khasia, Dafla and Naga Hills, in Assam"].

Endothyrella macromphalus 1899c Plectopylis (Endothyra) macromphalus , - Gude: Science Gossip, 6: 147, 148.

Endothyrella macromphalus 1899d Plectopylis (Endothyra) macromphalus , - Gude: Science Gossip, 6: 175, 177.

Endothyrella macromphalus 1914b Plectopylis (Endothyra) macromphalus , - Gude: The Fauna of British India …: 72, 79, figs 29 a–b.

Endothyrella macromphalus 1915 Plectopylis (Endothyra) macromphalus , - Gude: Records of the Indian Museum, 8: 507.

Endothyrella macromphalus 1915 Plectopylis (Endothyra) gregorsoni Gude new synonym: Records of the Indian Museum, 8: 506-507, Plate 41, figs 2 a–d. ["Yamne Valley, Abor Hills"].

Types.

Darjiling, coll. W. Blanford, NHMUK 1906.1.1.754. (holotype of macromphalus , Figure 23A); Yamne Valley, Abor Hills, leg. C.F.G. Oakes, R.E., NHMUK 1903.7.1.3124. (holotype of gregorsoni , Figure 23B).

Additional material examined.

Cherra, leg. Godwin-Austen, NHMUK 20150156/2 (juveniles, mixed sample with Endothyrella affinis ); Khasi, leg. Stoliczka, 1880.xv.194., NHMW 92589/1 juvenile shell; Khasi Berge, SMF 150102/3 (mixed sample with Endothyrella minor ); Khasi Berge, coll. Bosch, ex coll. Rolle, SMF 172069/2; Brit. Indien, Toruputu Dfola, 5000', coll. Ehrmann ex coll. Webb, SMF 150101/3; Dafla Hills, Burrail Gorge, coll. Godwin-Austen, NHMUK 1903.7.1.772/10 (4 had, 6 lacked a long lower plica); Khasi Hills, Mairang, coll. W. Blanford, NHMUK 1906.2.2.362/4 (3 lacked, 1 had a long lower plica); Khasi Hills, coll. Godwin-Austen, Figured in Godwin-Austen (1874), NHMUK 1903.7.1.766/9 (2 lacked, 7 had a long lower plica); Mairang, Khasi, NHMUK 1906.1.1.750/1; no locality, NHMUK 20150153/66 (19 shells had a long lower plica, 43 shells lacked, 4 corroded/dirty shells were not examined); Digny, coll. Godwin-Austen, NHMUK 20150154/1 (with long lower plica); Shillong, Khasi, "animal dissected", NHMUK 1903.7.1.773/1 (with long lower plica); Teria Ghat, coll. Godwin-Austen, NHMUK 20150155/1 (with long lower plica); Toruputu Pk., Dafla Hills, NHMUK 1903.07.01.769/2 (mixed sample with Endothyrella minor ); no locality, NHMUK 1871.9.23.68/4 (1 with, 3 without a long lower plica).

Diagnosis.

Shell very small, sinistral with relatively wide umbilicus, reticulated, almost flat spire (only the apex is elevated) and smooth umbilical side; callus weak, only very slight whitish lime layer is visible; palatal plicae straight, divided or not, lamella with short upper and lower plicae and two posterior denticles, one above and one below; the lower plica might be long (see under Additional material examined).

Measurements

(in mm): D: 5.5-8.2.2, H: 2.7-4.2 (n = 13, shells from different samples); the holotype of Plectopylis gregorsoni is 7.5 × 3.7 mm.

Differential diagnosis.

Endothyrella macromphalus has more depressed shells than Endothyrella blanda . Moreover, Endothyrella macromphalus shells are smooth on the ventral side, whereas most blanda shells have hairs, or in case of corroded Endothyrella blanda specimens, holes which indicate the hairs’ positions. Endothyrella dolakhaensis sp. n. is hairy, has weaker sculpture, and its spire is more elevated than in Endothyrella macromphalus . Endothyrella robustistriata sp. n. is smaller, has a narrower umbilicus and stronger dorsal sculpture. See also under Endothyrella williamsoni and Table 5.

Distribution.

Endothyrella macromphalus seems to have a wide range including Assam and the Dafla and Khasi Hills. It has been reported from the Naga Hills, but those samples are probably misidentified. Plectopylis gregorsoni (treated here as a synonym of Endothyrella macromphalus ) is recorded from the type locality only (approximately: 28°13.4'N, 95°13.3'E) (Figure 11).

Remarks.

The type specimen of Plectopylis gregorsoni is very similar to typical Endothyrella macromphalus specimens. The main difference is that the palatal plicae are not divided in gregorsoni , and the base is less glossy (rather weakly ribbed). In our view these minor difference are not sufficient for species level distinction, especially because Endothyrella macromphalus is a relatively variable species inhabiting wide geographical range. Very little is known about the distribution of specimens having divided or undivided palatal plicae. Therefore, until more information becomes available, Plectopylis gregorsoni is synonymised with Endothyrella macromphalus .