Vitrinidae

Ear -shaped glass snail ( Eucobresia diaphana )

The glass snails ( Vitrinidae ) are a native European family of housing and slugs the subordination of terrestrial snails ( gastropod ). Within the family can be seen very clearly the transition from housing to slugs.

Features

Most members of this family have a " slug -like " habit, as the animal can no longer withdraw completely into the thin, translucent housing. The name of the family is due to this thin, almost glass-like housing. The housing is generally low and dextral rolled up to four convolutions. It has a large opening and is usually shaped earrings. The opening is not constrained by teeth or calluses. The development of a snail on a slug ( with a small, rudimentary housing in the interior of the shell ) can be studied very well with this family; of forms that can be almost completely retract into the housing ( eg Vitrina pellucida ), about " half- slugs " as Vitrinobrachium breve, to " correct" slugs, in which the housing is enclosed by the mantle (eg Plutonia in the Azores ). The process of shell involution and the acquisition of slugs habit is referred to in the literature as Vitrinisierung.

Occurrence and life

The Vitrinidae usually live in moist to dry forests, quarries and rock landscapes of the plains to the mountains. Some species live mainly in the soil. The family is found in Europe, Western Asia, the Macaronesian Islands and East Africa. Few species are located in North America.

System

The glass snails are placed in the superfamily of Limacoidea be which include the slug ( Limacidae ), the slugs ( Agriolimacidae ) and the Wurmschnegel ( Boettgerillidae ) expected. The glass snail family has been divided by some authors into three subfamilies Vitrininae Fitzinger, 1833 Semilimacinae Schileyko, 1986 and Phenacolimacinae Schileyko, 1986. After Hausdorf (1998) Vitrininae are polyphyletic, the Semilimacinae Schileyko, 1986 paraphyletic and only the Phenacolimacinae Schileyko, 1986 monophyletic. The latter taxon is also a junior synonym to Plutoniinae Cockerell, 1893. He recommends abandoning the subfamily division for the time being.

• Family glass snails ( Vitrinidae Fitzinger, 1833) Genus Arabivitrina Thiele, 1931
• Genus Calidivitrina Pilsbry, 1919
• Genus Eucobresia H. B. Baker 1929 Ear -shaped glass snail ( Eucobresia diaphana Draparnaud, 1805)

The number of species is highly dependent on the individual authors, as some genera are divided into sub- genera ( eg the genus Plutonia ).