Atractophaedusa smithi is a species of air-breathing land snail, a terrestrial gastropod mollusk in the family Clausiliidae, the door snails.
This land snail lives in limestone areas in Vietnam. The original description was published in 2007, and included details of the reproductive system and the radula. The shell is sinistral in coiling and has 8 or 9 whorls.
The specific name smithi is in honor of Mr. Jady Smith, the project manager of the field research that resulted in the discovery of this species.
Distribution
This species occurs in: Vietnam
The type locality is Cát Bà Island, near the entrance of the Trung Trang Cave, 6.iv.2001, 20°47.38'N 106°59.87'E, Haiphong Province, Vietnam. All other known localities are also on Cát Bà Island.
Description
The shell is sinistral, not decollate, rather large, fusiform, solid, dark-brown, not translucent. Apical whorls are relatively broad. With 8-9 whorls, changing from apically moderately convex to somewhat flattened. Apical whorls are very finely, spirally punctated, the remaining ones with very fine, regular striae. The striae are rather faint above the aperture and not coarser on the neck. Suture is slightly indented. Neck is without a crest. Peristome is continuous, whitish, broadly reflexed and detached; basic margin more or less semicircular.
Peristome is double; inner lip recognizable as a narrow ridge, contacting the body whorl and closing the umbilicus (visible in not fully grown specimens); outer lip is protruding, forming a small, free tube. Aperture is pear-shaped, whitish inside, with a sinulus which is not defined at the palatal side. Lamella parietalis (= superior) very prominent, reaching the margin of the peristome, which is conspicuously curved at that site; its inner end merging into the lamella spiralis. Inside the shell, the lamella columellaris reaches somewhat further than ventrally, whereas both the lamella subcolumellaris and the spiralis are slightly shorter; without a lamella inserta. In frontal view, the lamella columellaris is visible as a low, nearly straight lamella, not reaching the margin of the peristome, whereas the lamella subcolumellaris reaches the margin of the peristome in most specimens. With six plicae palatales: plica principalis, shortly visible in frontal view, ventro-laterally accompanied by five short, somewhat curved plicae, increasingly diverging from the principalis and nearly running parallel which each other, so that the lowest one runs most obliquely. Inside the body whorl, the plicae are connected by a lunella-like ridge of callus. Clausilial blade is simple, ending with a sharp angle.
The width of the shell is 5.0 (8 whorls)-5.7 mm (9 whorls), on average 5.4 mm. The height of the shell is 18.6 mm (8 whorls)-22.3 mm (9 whorls), on average 20.5 mm.
Among the species in the genus Atractophaedusa, this species is most similar to the recently described Atractophaedusa antibouddah. The other species, viz. Atractophaedusa kebavica, Atractophaedusa pyknosoma, and Atractophaedusa rhopaloides, all have decollated shells when fully grown. Atractophaedusa smithi differs from Atractophaedusa antibouddah (of which a population was discovered at Vietnam, Quang Ninh Prov., Ha Long Bay area, unnamed island in Dau Moi Temper area, 13.ix.2003, 20°55.69'N 107°09.40'E – so far this species was only known from its type locality “Vietnam, Tonkin, 4 km from Cam Pha”) by the more slender shell, with a clearly visible lamella subcolumellaris, and by the shorter plicae palatales.