180 LAND AND ERESH-WATER MOLLUSKS. 
vulus) (PI. XL, fig. 138).—The shell resembles 
that of the last, but is more oval, and of a 
yellowish, or brownish-white colour; it is more 
ventricose, and has only two plaits on the pillar. 
The foot is deeply transversely divided, whereas 
that of 0. denticulatus is entire. 
Its habitats are the same as the last. It 
occurs in the south and west parts of England, 
and is pretty general along the Irish coasts. 
Otina otis, with a minute ear-shaped shell, 
is a marine species of the family Auriculidce ; 
it lives in the chinks of rocks at the margin of 
the sea in the south and south-west of Britain. 
The teeth resemble those of other Pulmonata , 
and are similar to Oonovulus . There are ten rows 
of sixty teeth in each. 
