Alycaeus carinata Maassen, 2006  

Maassen (2006) original descriptions on Alycaeus carinata – “Shell dextral, with a low conical spire and a large, keeled, body whorl. In this last whorl, at about ? whorl from the aperture, there is a transverse constriction. After that constriction, the shell widens again towards the aperture. From the constriction backwars a very small respiration tube lies along the suture. Fresh shells are citron yellow of light reddish brown; both the apical whorls and the last part of the body whorl near the peristome may be much lighter. Even at high magnification the first whorl is smooth; the following ones are covered by irregularly placed, oblique ribs, which are very thin and fragile lamellae, lying down at the surface. Only the ribs near the constriction are more or less normal ribs. At the underside of the flattened body whorl the ribs are faint or almost absent. Fresh shells are semitransparent and with dull lustre. Whorls4?, convex, regularly increasing in width for the first 3 ½ whorls; the last ¾ whorl increases considerably in width and it is here were the pointed keel starts. The suture is deep. Apex of the shell mamillate, its base flattened. Umbilicus open, very wide, showing all preceding whorls, only for a small part hidden by the reflected peristome. Aperture more or less circular, extremely oblique (about 30° with regard to the coiling axis) and protruding just beyond the peristome. Peristome very fragile, flat and expanded, not continuous, attached just below the angular side of the body whorl with a large, flaring edge; basally with another small edge. Just after the contriction the peristome bends slightly downwards until just beneath the keel. The body whorl has a pointed keel, which ends at the constriction; the remaining part of this whorl is well rounded. Operculum thin, corneous, round, with a concave outer surface and a convex inside.”