Plectostoma laemodes (van Benthem Jutting, 1961)  

Benthem-Jutting (1961) original descriptions on Opisthostoma (Plectostoma) laemodes – “Shell with regular, conical, rather plump spire, the last whorl ending in an irregular curve. At the transition of the normal spire and the irregular last part the whorl is transversely contricted. Straw-colour or light-pink, not transparent or shing. First 1 ½ whorls smooth, the following ones ornamented with fine, oblique ribs of the same colour as the shell. These ribs are rather distantly placed; on the last normal whorl before the constriction I counted 18 ribs in the holotype. After the constriction the ribs are placed at irregular intervals, sometimes closer together, sometimes wider apaert. On the terminal part I counted 12 ribs in the holotype. There is a delicate spiral striation. Whorls 6-7, the twisted part included and counted as if it regular. Convex, suture deep. Apex pointed, but not sharp, base rounded. Umbilicus narrow. Last whorl about halfway contricted transversely, then widening again towards the aperture, at the same time turning back, this falsely suggesting a sinistral shell. Aperture circular, vertical or a little oblique. Peristome continuous, adnate to the penultimate whorl. Just behind the peristome a wing-like collar runs parallel with it. Operculum unknown.”