Xerocrassa geyeri
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Xerocrassa geyeri Temporal range: early Pleistocene–Recent |
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| A shell of Xerocrassa geyeri | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): | clade Heterobranchia clade Euthyneura clade Panpulmonata clade Eupulmonata clade Stylommatophora informal group Sigmurethra |
| Superfamily: | Helicoidea |
| Family: | Hygromiidae |
| Subfamily: | Geomitrinae |
| Tribe: | Trochoideini |
| Genus: | Xerocrassa |
| Species: | X. geyeri |
| Binomial name | |
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Xerocrassa geyeri (Soós, 1926) |
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| Synonyms | |
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Xerocrassa geyeri is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Hygromiidae. It is also often known as Trochoidea geyeri.
Xerocrassa geyeri was originally described under the name Xerophila geyeri by the Hungarian malacologist Lajos Soós (1879-1972) in 1926. The specific name geyeri is in honor of the German zoologist David Geyer (1855-1932). The type specimens are stored in the Natural History Museum of Geneva.
Xerocrassa geyeri is a small land snail. The height of the shell is 3.4-6.0 mm, usually 3.5–5 mm. The width of the shell is 5.1(5.0)-8.0 mm.
The shell is globular in its shape. The shell has 4.5-5 whorls. Sometimes there are radial ribs on the surface of the shell forming its shell sculpture. There are usually no periostracal structures, but there can in some cases be hairs and in these cases, after the hairs are gone pits remain on the shel surface especially on the whorl below the apex. The color of the shell is greyish-white sometimes with one or a few brownish spiral bands.
The reproductive system of Xerocrassa geyeri was described by Gittenberger (1993): there is no appendage in the genital atrium, that is the distinguishing characteristic of the genus Xerocrassa Monterosato, 1892. There are two rudimentary dart-sacs near the mucus glands. The flagellum and the epiphallus have approximately the same length.
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