Phaedusa lucens Loosjes, 1953  

Loosjes (1953) original descriptions on Phaedusa lucens – “Shell of medium size, more or less turreted-fusiform, delicate, greenish, horn-coloured, shining, transparent. Spire slender with straight lateral outlines. Whorls 9 ½ to 11, mostly 10 (10 ½ for the holotype), slightly convex, to the naked eye almost smooth, only provided the faint tranverse striae, representing the growth-lines; they are definitely coarser and slightly wavy on the neck. There is a faint thread running along the suture. Nuclear whorls 2 ½, almost smooth. The neck bends regularly and slowly towards the base of the aperture. The penultimate whorl is widest. Aperture quadrangular egg-shaped; horn-coloured within; the sinulus is separated from the rest of the aperture only by the lamella superior. As the basal edge of the peristome lies slightly backward the plane in which the peristome lies runs parallel to the axis only in the upper half. The peristome is continuous, white, somewhat widened and reflexed: the margin is narrow, the upper margin is clear of the preceding whorl: where it touches the lamella superior, there is no angle. The base of the peristome is regularly rounded, the sides of the margin run almost parallel: from the top of the sinulus the parieto-columellar side gradually descends to the right to a point ventral of the closed umbilicus, from there it goes down fairly straight. Lamella superior is of moderate height, reaching the margin; its inner end is clear of the lamella spiralus and approaches the lamella inferior. The lamella spiralis ends in the aperture at the left side and runs inward, increasing in height towards the right side; it ends rather abruptly in a ventral position. Lamella inferior is seen in the aperture at the right side as a low fold, not reaching the margin, running inward and upward; it soon becomes high, in such a way that the thickened edge disappears almost horizontally. It ends beyond or together with the other lamellae in a ventral position. When one looks into the aperture the inner side of the base of the inferior lamella is hardly visible. Lamella subcolumellaris is not or scarcely discernible in the aperture: it ascends straight upwards. The closing apparatus liesa just between the dorsal and the right side. The plica palatalis principalis runs from dorso-lateral at the left side to the right side; it is about 3/8 whorl long. Below and near the principalis we find 1 or 2 plicae palatals in a dorso-lateral position. There are no plicae in the middle of the whorl, but just above the closed umbilical slit is a third short fold, more or less parallel with the upper ones. The lamella subcolumellaris may be seen from outside through the shell, just above and at the right side of the umbilicus. The plate of the clausilium is strongly curved at one third from the top; the sides diverge from the pedicle up to about the same place, the top is slightly thickened. The dimensions of the plate are: length 2.6 mm, width 1.5 mm.”