Discartemon discamaximus Siriboon & Panha

Siriboon, Thanit, Sutcharit, Chirasak, Naggs, Fred, Rowson, Ben & Panha, Somsak, 2014, Revision of the carnivorous snail genus Discartemon Pfeiffer, 1856, with description of twelve new species (Pulmonata, Streptaxidae), ZooKeys 401, pp. 45-107 : 60

7. Discartemon discamaximus Siriboon & Panha sp. n. Figs 5A, B, 23, Table 1

Type material.

Holotype CUMZ 6245 (Fig. 5A). Measurement: shell height 4.7 mm, shell width 14.6 mm, and with 7 whorls. Paratypes: CUMZ 6005 (2 shells) and NHMUK 20130673 (2 shells) from the type locality.

Other material examined.

Tam Kobe, Phangnga: CUMZ 3669, 6197.

Type locality.

Tam Namphud, Phangnga, Thailand, 8°27'46.8"N, 98°32'30.5"E.

Diagnosis.

The characters distinguishing Discartemon discamaximus sp. n. from Discartemon sykesi and Discartemon khaosokensis are the larger shell with flattened to concave spire, the transverse ridges present near the suture, and the lack of a sinulus. Discartemon discamaximus sp. n. has similar shell morphology to Discartemon discus and Discartemon discadentus sp. n., but is distinguished by having the transverse ridges present only near the suture and the last whorl rapidly expanded. Discartemon discadentus sp. n. also has five apertural lamellae.

Description.

Shell. Shell flattened, white and translucent; whorls 7, spire flattened to concave, with distinct suture. Shell surface glossy with transverse ridges near suture and varices present. Embryonic shell large, about 2½ whorls, with smooth surface; following whorls regularly coiled. Last whorl angular, rapidly expanded; umbilicus very wide and showing all preceding whorls. Aperture semi-ovate; peristome discontinuous, expanded and reflected; apertural dentition with one parietal lamella (Fig. 5A).

Etymology.

The specific epithet “discamaximus” is derived from the Latin “discus” meaning “disc” and “maximus” meaning "large or broad".

Distribution.

This new species is known from limestone karst near Phanganga Bay reaching about 100-400 meters amsl, surrounded by the Phuket mountain range.

Remarks.

To date no living specimens have been found.