158 LAND AND FRESH-WATER MOLLUSKS. 
escape notice. The animal is sluggish, and is 
not frequently to be seen stirring about. 
Genus Vertico (Whorl Snails). 
The animal differs from that of Pupa in being 
destitute of the lower pair of tentacles. The 
shell is minute, sometimes sinistral; the peri- 
stome is thinner than in Pupa. Of the nine 
species inhabiting this country, V. Moulinsiana 
is the only one not known in a fossilized state. 
The species may be distinguished as follows :— 
Nad 
Shell dextral . 2 
Shell sinistral ... 8 
2 Aperture edentulous 3 
* ( Aperture toothed sheue Conemete 4 
Shell small, slightly striated ... 1... ... OV. 7. ee 
Shell minute, strongly striated ... V. minutissima 
4 “SIEM 03:7 | Soe ale a 5 
* {Shell cylindrical... 7 
Aperture toothed... ... 6 
5, ¢ Aperture with many ‘teeth, aperture contracted, — 
V. antivertigo 
6 SIE eTT ccys ess’ sea, eee one-one 
* ( Shell large Sh oe wee ee) )6 Ve Moulinsiana 
Shell subcylindrical, ea 1 ae Vi apeetras 
7. « Shell inclned to fusiform, strongly striated,— 
V. substriata 
Aperture subquadrate, six to seven teeth,—V. pusilla 
8. < Aperture triangular, contracted, four to six ‘teeth, — 
ha angustior 
