Carinartemis Siriboon & Panha, 2014

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 : 166-168

Carinartemis Siriboon & Panha , new genus

Type species. Carinartemis vesperus Siriboon & Panha , new species.

Diagnosis. This new genus is noticeably distinct from Discartemon and Perrottetia by having a strong peripheral keel around nearly the entire penultimate whorl, in having the last whorl less inflated but strongly deviated from the vertical axis, and in having or lacking very thin parietal lamella. Whereas, Discartemon possesses a regularly coiled shell, the last whorl does not deviate from the columellar axis, and the apertural dentition varies, with at least a parietal lamella present. Perrottetia also has a smaller shell, has longitudinal furrows on outer wall of the last whorl, and always has two parietal and the other lamellae present.

In comparison, Oophana and Indoartemon have a more inflated last whorl, while the penultimate whorl is rounded to angular. Oophana has parietal, palatal, basal, and columellar lamellae, and Indoartemon has only parietal and palatal lamellae.

The new genus, Carinartemis , is superficially similar to Haploptychius and Stemmatopsis with the last whorl less inflated and much deviated from the vertical axis, and in having or lacking a lamella. However, Haploptychius differs from this new genus by having an angular to round peripheral keel around less than half of the penultimate whorl, and with a strong parietal lamella always present. The monotypic Stemmatopsis Mabille, 1887 is smaller, has a lower spire, a smooth shell surface, a rounded periphery of penultimate whorl, closed umbilicus, an aperture with an irregularly constricted shape, and a sinuous peristome ( Fig. 6A ; Mabille, 1887).

Description. Shell suboblique-heliciform, white, and translucent; whorls 7, spire low conical with distinct suture. Shell surface with transverse ridges. Embryonic shell with smooth surface; following whorls regularly expanding and penultimate whorl with very sharp and wide peripheral keel. Last whorl round and axially deflected. Umbilicus open and deep. Aperture subcircular, peristome expanded. Apertural dentition with or without parietal lamella and sometimes small other lamellae present.

Genitalia with short atrium; penis long; penial sheath thin to thick. Internal wall of introverted penis with brown penial hooks. Vagina short, free oviduct short to long. Seminal vesicle about as long as the length from the talon to the branching point of the seminal vesicle. Internal wall of vagina with oblique to arched parallel vaginal folds; vaginal hooks may be present.

Live specimens exhibit pale yellowish reticulated skin with brownish spots, and yellowish tentacular retractor muscles are visible through the semi-transparent body ( Fig. 2B, C ). Etymology. The generic name Carinartemis is derived from the Latin “ carina ” meaning “keel”, and Greek “ artemis ” meaning “goddess of the chase”. It refers to this carnivorous snail that has a prominent peripheral keel on penultimate whorl.

Remarks. The new genus currently comprises two new species. They are uncommon and seemed to be restricted to the limestone outcrops in western Thailand.

Figures

Fig. 6. A, Shell of Stemmatopsis poirieri lectotype MNHN 26980; B–E, Shells of Carinartemis vesperus, new species, (B) holotype CUMZ 5019 with apertural dentition, (C, D) paratype CUMZ 6200 from Khao Kling, Khao Yoi District, Phetchaburi, and (E) specimen NMW 1955.158.25233 from Khao Yoi, Petchaburi; F, G, Carinartemis striatus, new species, (F) holotype CUMZ 6203 with apertural dentition, and (G) paratype CUMZ 6117 from Tam Kra Sae, Sai Yok, Kanchanaburi.

Fig. 2. Living snails of: A, Indoartemon medius, new species, paratype CUMZ 5017 (shell width about 8 mm); B, Carinartemis vesperus, new species, paratype CUMZ 6201 (shell width about 10 mm); C, Carinartemis striatus, new species, paratype CUMZ 6205 (shell width about 12 mm).