ROMSO Cyprus Knowledge Base

--- CONTENT ---
The wide-ranging crystal snail (Vitrea contracta) is a land-dwelling snail species of crystal snails (Pristilomatidae) in the subordination of land-lung snails (Stylommatophora).

Features
The right-handed, rather small housing is strongly flattened-conical, almost thick-disk-shaped. In the adult state, the housing measures 1.8 to 3.0 (usually around 2 mm) in width (diameter) and 1.0 to 1.4 mm in height. In side view, the thread is only slightly raised. There are adult 4 to 5 turns, which increase slowly and regularly. The last turn is comparatively narrow. Seen from above, it occupies only about 1.4 to 1.6 times the previous turn. The upper side of the turns is curved flat, the seams are therefore also very flat. The periphery is well rounded, the underside relatively flat. The mouth would be flattened-elliptical in the complete outline, oblique-creescent-shaped by the deep incision of the previous turn. The mouth edge is straight and sharply tapered, not thickened by a lip. The navel is deep and wide and continues with the last turn. All circuits are visible in the navel.

The shell is colorless, and glassy transparent to slightly milky. The surface shines strongly. Very fine irregular growth strips and, for a hint, spiral lines are present.

In the twelfth sex apparatus, the sperm duct is quite short. It penetrates apically through a simple pore into the penis. The penis is slender and spindle-shaped. The penile retractor muscle attaches apically to the penis. The free fallopian tube is very short, the vagina relatively long, about as long as the penis. The vagina is surrounded in the distal part by a weakly pronounced perivaginal gland. The sperm library is reduced to a finger-shaped, small extension or even completely missing. The atrium into which the penis and vagina end is comparatively long.

Similar species
The case of the wide-bed crystal snail is slightly less thick (high) than that of the common crystal snail (Vitrea crystallina), and on average slightly smaller. The last turn is narrower and the bottom is flatter. The navel is slightly wider and not eccentric. The mouthline does not thicken. In contrast to the Common Crystal Snail, however, the Wide-Seated Crystal Snail prefers slightly drier and lime-richer biotopes. But it also tolerates slightly wet habitats. Therefore, both species occasionally occur together. The Ungeabelte crystal snail (Vitrea diaphana) and the Enggeabelte crystal snail (Vitrea subrimata) are distinguished by the closed or almost closed navel.

Geographical distribution and habitat
The distribution area extends over wide areas of Western, Central and Southern Europe. In the north it extends to southern Scandinavia and the coastal area of southern Finland. In the east to the Baltics, Belarus, Western Russia and Western Ukraine. It is missing i