Ibycus perakensis (Godwin-Austen, 1909)
“This species has most interesting similarity to Leptodontarion hiraseanus from Formosa, both in the jaw and radula and outward form, even to the globose shape of the shell, but hiraseanus is even more globose. The generative organs differ in the presence of the amatorial organ and in other details. Its relationship is therefore closer with the Indian species, L. minuta of Assam, as might be expected, than with the Formosan form.” (Godwin-Austen, 1909)
Godwin-Austen (1909) original descriptions on Leptodontarion perakensis – “Shell very globose, thin, and membranaceous; spire low, apex rounded; peristome somewhat sinuate; suture moderately impressed; no sculpture, smooth, shiny; colour ochraceous green; whorls 3½; aperture and columellar margin not seen. Only one specimen received, and to examine the animal the shell was broken to extract it. Major diam. 6.3 mm.; diam. of shell figured 5.5 mm. Animal pale-coloured throughout, without markings of any kind. The right shell lobe rolled up by contraction in the spirit; it is long, fairly wide, of even breadth at first, then narrowing, and in life would cover the portion of the shell below and on side of the periphery. The young specimen from the Cambridge Museum, a good deal contracted by the spirit, shows the right shell lobe unfolded. There is a very small left shell lobe. The right dorsal lobe is large and triangular, the left dorsal lobe in two distinct lappets. The foot is pointed and has a long overhanging lobe. The peripodial grooves are well marked, sole indistinctly divided. Length of the animal about 16 mm. The jaw is nearly straight, narrow, the cutting edge slightly concave; it is thin and transparent, arched above, merging into the muscular tissue. The radula consists of numerous rows of similar curved teeth having a great number in a row, on long narrow plates. The centre tooth is unicuspid, very long and pointed, the base gradually widening out. All the admedians are nearly evenly bicuspid, the outer cusp being very slightly the longer. The genitalia were not got out quite perfect. An amatorial organ with a blunt point is present, also a short ovoid spermatheca with club-like free end; the penis was broken off.”
Leptodontarion perakensis – “Major diam. 6.3 mm.; diam. of shell figured 5.5 mm." (Godwin-Austen, 1909)
Type locality – “Talum, Perak” Leg. Dr. Townsend (Godwin-Austen, 1909)
Other locality – Malay Peninsula; Larut Hills, Perak, alt. 4500 alt” (Laidlaw, 1933)