Amastra extincta
Amastra extincta is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae.
Description
The length of the shell attains 16 mm, its diameter 7.5 mmThe 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.