160 LAND AND FRESH-WATER MOLLUSKS. 
is distinguished from that species by its very 
minute size, and in the strongly striated surface 
of the shell. It occurs here and there in Eng- 
land and Scotland; it harbours under stones on 
hills, chiefly those that are limestone. In Scot- 
land it occurs in Skye; Balmerimo, Fifeshire ; 
Arthur’s Seat. In England, on magnesian lme- 
stone, Falcon Clints, near Sunderland ; and near 
Pontefract, in Durham; Wakefield, and Went 
Vale, Yorkshire; Durdham Downs, Bristol ; 
Sulworth, in Dorset; and on the Undercliff, in 
the Isle of Wight. Its minute size may account 
for its apparent rarity. It is a continental 
species, and widely diffused. 
Vertigo premma—(the Pigmy Whorl Shell) 
(Pl. [X., fig. 90).—The shell is oval, about one- 
tenth of an inch long, of a brown shining colour ; 
the four or five whorls gradually increase in size ; 
the aperture is dextral, with a slightly reflected 
margin, and provided usually with four teeth, 
one of which is central on the upper side or 
pillar. 
This is one of the most widely distributed of 
the Vertigos ; it may be easily procured under 
stones upon dry and elevated situations. 
A thinner shell, and of a lighter colour than 
the typical form, is known to collectors; I have 
found it under stones on the shores of the Irish 
upland lakes, and in damp fields in England. 
ae Meo 
! 
