Amastra extincta
Species of mollusc
From Wikipedia, the free encyclopedia
Amastra extincta is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae.[1]
| Amastra extincta | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Amastridae |
| Genus: | Amastra |
| Species: | A. extincta |
| Binomial name | |
| Amastra extincta (L. Pfeiffer, 1856) | |
| Synonyms | |
| |
Description
The length of the shell attains 16 mm, its diameter 7.5 mm
The shell is perforate, ovate-turrite, solid, and finely striate, with a chalky texture. The spire is long, tapering upwards, and acute. There are 7 whorls, which are scarcely convex, with the body whorl comprising less than one-third of the total shell length and slightly compressed around the perforation.
The aperture is slightly oblique, rhombic-oval, and angular at the base. The columellar fold is compressed and ascends almost from the base. The peristome is simple and unexpanded, with the margins connected by a thick, somewhat nodular callus. The columellar margin is dilated and free.[2]
