Pseudonenia scalariformis Loosjes, 1953
Loosjes (1953) original descriptions on Pseudonenia scalariformis – “Shell of medium height, turreted, rather delicate, yellowish-brown, slightly glossy, transparent. Spire slender, scalariform, with straight lateral outlines. Whorls 12 ½, convex, sculptured with very faint growth-lines, almost smooth; only the neck shows transverse striae (it is not possible to give the exact number to the mm); a thread in the colour of the shell runs below the rather deep suture. The nuclear whorls are smooth, cream-coloured, and form a rather sharp apex. A band on the whorls below the suture is cream-coloured. In a side view the neck is very slowly bent towards the base of the aperture. Aperture oblique, small and triangular ovate, horn-coloured within, the sinulus is broad but not high, the parietal margin is distinctly bent where it is touched by the superior lamella. The base of the peristome is receding, the top of the sinulus also recedes. The peristome is continuous and has the colour of the shell, not reflexed but a bit widened like a trumpet, the margin is slightly thickened. The upper margin is clear of the preceding whorl, it is curved where it is touched by the lamella superior. From the sinulus the outer and the parieto-columellar margin are both curved down regularly. Lamella superior is of intermediate height, reaching the margin, connected with the lamella spiralis. Lamella inferior is visible in the aperture as a rather low fold, which quite soon turns inward and upward into the shell. At the dorsal side, the inferior lamella is not very high, its outer end does not reach the margin. When looking obliquely from below into the aperture, one cannot see the base of the inferior lamella. The columellar edge is not very distinct. The lamella subcolumellaris is strong. It runs towards the margin of the peristome. I did not study the inner ends of the lamellae, because I did not want to open the only available specimen. The closing apparatus lies a little ventrally at the right side. The plica palatalis principallus lies rather far away from the suture, it is a half whorl long and runs from the ventral to the dorsal side. Below it we find 3 palatal plicae of which the upper two are longest, parallel and running from the ventral to the right side; the lowest is short, it lies at the ventral side near the curvature of the upper peristomal margin. The lamella subcolumellaris is not scarify the type-specimen.”
Pseudonenia scalariformis – “Length of the shells: 21.1 mm, diam. 3.5 mm; aperture: height 3.8 mm, width 2.4 mm, number of whorls: 12 ½.” (Loosjes, 1953)
Type locality – “Borneo: Sarawak, Mount Poe, altitude 1000 m.” leg. F. F. Laidlaw (Loosjes, 1953)