Popis
Autor: Jan Delsing
Text ID: 89473
Text Type: 1
Page: 0
Založeno: 14.08.2018 00:34:50 - Uživatel Delsing Jan
Poslední změna: 06.03.2024 21:03:52 - Uživatel Delsing Jan
Language: EN
Odkazová funkce: [[t:308548,textblock=89473,elang=EN;Popis]]
Chrysallida doliolum: The shape of the shell varies from pupoid and slightly conical (B/b = 1.5) to slender (L/B = 3.0) and nearly cylindrical (B/b = 1.1). The protoconch is of type B, tending to A ("planorboid", or "Al"). Frequently, part of the first half whorl is visible, its suture is brown. There are four, exceptionally five, flat to barely convex teleoconch whorls. The suture is narrow, wavy because of the somewhat bulging upper parts of the ribs and lies somewhat obliquely to the shell axis. The ribs are broad, and close-set, the interstices narrow. These may continue to the base of the last whorl or decrease and disappear around the upper part of the aperture. They are straight (seldom sinuous) and vertical or somewhat leaning to the right. Generally, both directions occur in one shell, whereby the highest and the lowest whorls show vertical ribs, and those in between are markedly opisthocline. There are no spirals. The aperture is relatively small, egg-shaped and narrowing towards its upper side. There is a small tooth-pleat, no umbilicus and no umbilical chink. C. doliolum is the only coloured European Chrysallida. The basic colour is yellow-white to yellow. There are orange-brown lines or bands on the whorls. Furthermore, there is a broad band at the upper side of the initial whorls, just under the suture, and sometimes a second, narrow spiral line just at their bottom, close to, or even within, the suture. The lowest whorl has three spiral bands: the upper one (the broadest) just under the suture, the middle one just above the aperture, and the lowest one alongside the aperture, starting just above the tooth fold. Measures: Length 1.8-2.5 mm, LW 48-58%, A 26-31%, L/B 2.2-3.0, B/b 1.1-1.5 (based on 21 shells).
Van der Linden, J. & Eikenboom, J.C.A., 1992. On the taxonomy of the Recent species of the genus Chrysallida Carpenter from Europe, the Canary Islands and the Azores (Gastropoda, Pyramidellidae)