Phaedusa filicostata filialis (Von Martens, 1903)  

Martens (1903) original descriptions on Clausilia filialis – “Testa elongate turrita, leviter striatula, corueo-fusca, sutura superficiali, simplice; anfr. 13, priores 4-5 convexi, sequentes subplani, antepenultimus et penultimus aequales, ultimus paulo angustior cervice rotundata, non rugosa, ad basin leviter impressa; apertura patula, trigono-piriformis, paulum obliqua, peris tomate sat tenui, breviter expanso, albo; lamella superior debilis, marginem attingens, retrorsum rectilinear et magis elevata, lamella inferior paulo validior, parum flexuosa, in marginem excurrens; pl. subcolumellaris non emersa; plicae palatales (inclusa principali) 3, subaequaliter ultra lunellam prolongatae, in fauce breviter conspicuae et extus sulcis impressis notatae, lunella extus aegre conspicua.”

Loosjes (1953) descriptions on Phaedusa filicostata filialis – “Shell large, turreted-fusiform, fragile, yellowish-horn-coloured, slightly glossy, transparent. Spire conical, slender, gradually broadening; with slightly convex lateral outlines. Whorls 13, the lowest flat, sculptured with numerous transverse, fine, wavy striae (about 12 to the mm on the whorl above the aperture), which are distinctly coarser and stand wider apart on the neck. There is a distinct thread in the colour of the shell below the shallow suture. Nuclear whorls about 3, faintly striated, indistinctly separated from the lower whorls, as these are but little wider at the transition. The last 3 whorls together form a cylinder, they form the lowest half of the shell. In a side view, the neck regularly and slowly curves towards the base of the aperture. Aperture pear-shaped triangular; the sinulus is almost entirely formed by the lamella superior, for there is only a faint angle in the peristome. The peristome is continuous, whitish; as it is much damaged it is impossible to record whether it was broadly reflexed or not; the upper margin is clear of the preceding whorl. From the sinulus the outer margin runs in a slow curve, the parieto-columellar margin runs down slowly at the right side. There it has a faint angle and then runs down almost straight, but a little to the right. The base of the aperture is rather wide and rounded. Lamella superior of moderate hight, reaching the margin; there is a wide gap between its inner end and the outer end of the lamella spiralis. Lamella inferior is seen as a low fold, ending in the middle of the columellar side of the aperture, not reaching the margin. Halfway the visible columella a fork-like structure. The base of lamella inferior is visible, if one looks from below and from the right side into the aperture. Behind the inferior lamella the lamella subcolumellaris is visible in an oblique view of the aperture. The position of the inner ends of the lamellae is unknown to me, as the only available shell could not be opened. The closing apparatus lies at the right side, the upper plicae lie in a rather dorsal position. The plica palatalis principalis runs from dorsolateral-left to ventrolateral-right. Below it and parallel with it runs a distinct groove, which is certainly an individual deviation, the shell had been damaged here. There are 8 plicae palatals, arranged in a faint, almost horizontal curve. This curve runs down from dorso-lateral to ventro-lateral, close to the right (parieto-columellar) upper angle of the peristome. The top and second plicae are longest. Below this row of plicae, which are for the greater part rather short, the lamella subcolumellaris is visible through the shell. Clausilium unknown.”