Endothyrella serica (Godwin-Austen, 1875)

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 : 14-17

Taxon classification Animalia Pulmonata Plectopylidae

Endothyrella serica (Godwin-Austen, 1875) Figures 5 B–D, 6B

Endothyrella serica 1875 Helix (Plectopylis) serica Godwin-Austen: Proceedings of the Zoological Society of London: 608, 609, 612, Plate 73, figs 5 a–c. ["on the peak of Henozdan, Burrail range" "above 5000 feet on the same range as far east as the Kopamedza ridge"] (1874, part IV, published in 1875; see Duncan 1937).

Endothyrella serica 1875 Helix (Plectopylis) munipurensis Godwin-Austen new synonym: Proceedings of the Zoological Society of London: 610, 612, Plate 73, figs 6 a–c. ["At the end of the Ihang valley, Munipúr, at about 3000-4000 feet"] (1874, part IV, published in 1875; see Duncan 1937).

Endothyrella serica 1875 Helix sericata (sic.), - Hanley & Theobald: Conchologia Indica...: 53, Plate 132, figs 8, 9.

Endothyrella serica 1878 Helix (Plectopylis) serica , - Nevill: Hand list of Mollusca in the Indian Museum, Calcutta...: 71. ["Hengdan Peak and Burrail"].

Endothyrella serica 1879a Helix (Plectopylis) serica , - Godwin-Austen: Journal of the Asiatic Society of Bengal, 48 (2): 3.

Endothyrella serica 1887 Helix (Plectopylis) serica , - Tryon: Manual of Conchology …, 2 (3): 159, Plate 34, figs 49-52.

Endothyrella serica 1887 Helix (Plectopylis) Munipurensis , - Tryon: Manual of Conchology …, 2 (3): 160, Plate 34, figs 56-58.

Endothyrella serica 1897a Plectopylis serica , - Gude: Science Gossip, 3: 205-206, figs 31 a–c.

Endothyrella serica 1897 Plectopylis serica , - Gude: Science Gossip, 3: 246.

Endothyrella serica 1898 Plectopylis munipurensis , - Gude: Science Gossip, 4: 263-264, figs 69 a–g.

Endothyrella serica 1899c Plectopylis (Chersaecia) serica , - Gude: Science Gossip, 6: 148.

Endothyrella serica 1899c Plectopylis (Chersaecia) munipurensis , - Gude: Science Gossip, 6: 148.

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

Endothyrella serica 1899d Plectopylis (Chersaecia) munipurensis , - Gude: Science Gossip, 6: 175, 176.

Endothyrella serica 1914b Plectopylis (Chersaecia) serica , - Gude: The Fauna of British India …: 73, 93-94, figs 40 a–c.

Endothyrella serica 1914b Plectopylis (Chersaecia) munipurensis , - Gude: The Fauna of British India …: 73, 94-95, figs 41 a–g.

Types.

Khunho, H.S. Naga Hills, leg. Godwin-Austen, NHMUK 1903.7.1.741 (8 syntypes of serica , Figure 5B); Hengdan P., Naga Hills, leg. Godwin-Austen, NHMUK 1903.7.1.744 (6 syntypes of serica , Figure 5C); Munipur Hills, head of the Ihang valley, Munipur, leg. Godwin-Austen, NHMUK 1903.7.1.742. (6 syntypes of munipurensis , Figure 5D).

Additional material examined.

Naga Hills, coll. Godwin-Austen, NHMUK 1903.7.1.743/4 (under the name munipurensis ); Japvo Peak, Nr. Kohima, Naga Hills, NHMUK 20150128/8; Lhota Naga, coll. Godwin-Austen, NHMUK 1903.7.1.745/6; no locality, leg. Maxwell, coll. Godwin-Austen, NHMUK 20150129/5; India, Hengdan Peak, NHMUK 1891.3.17.356-357/2; India, NHMUK 1874.4.26.2/2; Khasi Hills, coll. W. Blanford, NHMUK 1906.2.2.360/2.

Diagnosis.

Shell very small to small, dextral, yellowish-reddish striped with moderately wide umbilicus and depressed conical dorsal surface; callus strong, palatal plicae more or less straight, simple or have dichotomously divided posterior ends; parietal wall with a single curved lamella with denticles near the upper and lower ends posteriorly, which occasionally fuse with the lamella.

Measurements

(in mm): D: 9.7-9.9, H: 4.4-4.8 (n = 3, NHMUK 1903.7.1.744); D: 9.9-13, H: 4.9-5.5 (n = 4, NHMUK 1903.7.1.741); D: 10.9-11.7, H: 5.1-5.7 (n = 3, NHMUK 1903.7.1.742).

Differential diagnosis.

Endothyrella babbagei and Endothyrella inexpectata sp. n. differ from Endothyrella serica by the flat dorsal surface of the shell and the presence of three rows of hairs on the body whorl. Endothyrella oglei differs from the also dextral Endothyrella serica by the much larger size, the absence of the groove on the protoconch, which runs parallel with the suture in Endothyrella serica , and the morphology of the lamella which has only posteriorly elongated ends. See also Table 5.

Distribution.

The species is recorded from the Naga Hills (see also remarks). " Plectopylis munipurensis " was described from "end of the Ihang valley" (Figure 11).

Remarks.

Godwin-Austen (1875) described Helix (Plectopylis) serica and Helix (Plectopylis) munipurensis in the same publication. He did not mention the differences between the two species. According to the illustrations and the identification key in the original description, the upper end of the lamella in munipurensis is more elongated anteriorly than that of Helix serica . Two shells of Endothyrella serica were opened from the Hengdan sample, and both had an anteriorly elongated plica. In this respect, and also in shell shape, these shells were more similar to Endothyrella munipurensis specimens. In the Khunho sample four shells were opened, three having no or very slight upper elongation, but one had an as long plica as in typical munipurensis shells. Examining the type specimens of the two species we have not found significant differences. The width of the umbilicus and the height of the spire showed some variability. Therefore we synonymize munipurensis with serica . We choose Helix (Plectopylis) serica to be the valid specific name.

In the original description Godwin-Austen (1875) reported the species from the "peak of Henozdan" and from the "Kopamedza ridge". The second sample is probably identical with the one from Khunho in the type collection of the NHM.

Gude (1897h) mentions that according to Godwin-Austen, the correct names for “Henozdan” and “Kopameda” in Gude (1897a) are “Hengdan” and “Kopamedza”, respectively. According to the same erratum, Godwin-Austen also mentioned that the locality of Ponsonby’s shell (Sylhet) is probably incorrect, because Plectopylis serica is a very local species, inhabiting altitudes higher than 5000 feet.