Indoartemon eburneus ( Pfeiffer, 1861 )

Siriboon, Thanit, Sutcharit, Chirasak, Naggs, Fred, Rowson, Ben & Panha, Somsak, 2014, Revision of the carnivorous snail genus Indoartemon Forcart, 1946 and a new genus Carinartemis from Thailand (Pulmonata: Streptaxidae), Raffles Bulletin of Zoology 62, pp. 161-174 : 162

Indoartemon eburneus ( Pfeiffer, 1861)

( Figs 1 , 3A, B , Table 1)

Streptaxis eburnea Pfeiffer, 1861: 23 . Type locality: Cochin China.

Streptaxis eburneus: Pfeiffer, 1868: 447 . Gude, 1903: 226, pl. 4, figs 4–6.

Odonartemon (Odonartemon) eburneus: Kobelt, 1905: 91 , 92, pl. 58, figs 21–23. Thiele, 1931: 730.

Oophana (Indoartemon) eburnea: Forcart, 1946: 215 .

Indoartemon eburneus: Zilch, 1960: 562 , fig. 1196.

Material examined. A single syntype in the H. Cuming collection is designated here as the lectotype NHMUK 20120255 ( Fig. 1A ). Additional record CUMZ 5014 (16 shells; Fig. 1C ), Wat Tam Phalom , Loei, Thailand. Limestone hills 400–600 m above the mean sea level (17°33'17.1"N, 101°52'4.3"E) .

Remarks. The oblique-heliciform shell possesses 7½ whorls and is a translucent glossy white with distinct sutures; fine transverse ridges diminish below the periphery. The embryonic shell is smooth and large with about 2½ whorls. The periphery is shouldered, the last whorl axially deflected and umbilicus open. Aperture semi-ovate, peristome discontinuous and expanded. Apertural dentition with one parietal and one palatal lamella ( Fig. 3A ).

Indoartemon laevis ( Blanford, 1899) from Myanmar is distinctive with a smaller shell, lower spire and a basal lamella. Indoartemon eburnea is superficially similar to I. cingalensis from Sri Lanka, however, the last whorl is less deviated from the vertical axis and a columellar lamella is present.

Shells from Thailand ( Fig. 3B ) are slightly larger than the lectotype ( Fig. 3A ). However, apertural dentition and shell shape correspond and the size difference is interpreted as intra-specific variation .

Figures

Fig. 1. Distribution map of Indoartemon spp. and Carinartemis spp. Indoartemon spp (white circle): (1) Indoartemon cingalensis (Benson, 1853); (2) Indoartemon layardianus (Benson, 1853); (3) Indoartemon glacilis (Collett, 1898); (4) Indoartemon eburneus (Pfeiffer, 1861); (5) Indoartemon fuchsianus (Gredler, 1881); (6) Indoartemon bidens (Möllendorff, 1883); (7) Indoartemon tridens (Möllendorff, 1898); (8) Indoartemon laevis (Blanford, 1899); (9) Indoartemon prestoni (Gude, 1903); and (10) Indoartemon medius, new species. Carinartemis spp. (black circle): (1) Carinartemis vesperus, new species; and (2) Carinartemis striatus, new species.

Fig. 3. Shells of Indoartemon spp: A, B, Indoartemon eburneus, (A) lectoype NHMUK 20120255, and (B) specimen CUMZ 5014, with apertural dentition, from Wat Tam Phalom, Loei; C, D, Indoartemon prestoni, (C) lectotype NHMUK 1922.8.29.5, and (D) specimen CUMZ 5015, with apertural dentition, from Wat Tam Ra-Khang, Si Samrong, Sukhothai. E–G, Indoartemon medius, new species, (E) holotype CUMZ 5016 with apertural dentition, (F) paratype CUMZ 5017, and (G) specimen CUMZ 5018 from Tam Lom-Tam Wang, Si Samrong, Sukhothai.