LAND SNAILS. 
99 
dried, to remove tlie moisture and harden the 
soft parts remaining; but the heat must not be 
too great, or else the shells will be discoloured, 
and are liable to be broken. And, further, the 
specimens should be well dried before placing 
them in the cabinet, which should be in a well- 
ventilated place, free from damp ; for their fresh¬ 
ness and beauty are apt to be lost by the growth 
of fungi upon their surfaces. 
The following synoptical table represents 
the genera into which the family Helicidce is 
divided 
T Shell oval ... ... .. Succinea 
1. < „ globular or depressed, month transverse ... 2 
l „ more or less cylindrical, mouth longitudinal 4 
^ ( Shell glassy, outer lip thin . 3 
( „ not glassy, outer lip usually reflected ... Helix 
2 ( Shell imperforated . Vitrina 
* „ umbilicated . Helicella 
Shell fusiform, sinistral.. ... ... . . 5 
„ turreted . 6 
„ subcylindrical... 7 
„ oblong . 8 
Aperture with a clausimn .. ... Clausilia 
No clausium, aperture toothless .. Balea 
s. j Columella truncated in front ... . Achatina 
\ Front entire . Bulimus acutus 
( Shell dextral, animal with four tentacles ... Pupa 
7. < „ sinistral or dextral, lower tentacles 
( obsolete ..., Vertigo 
g (Shell polished ... .. ... ... ... ... ... 9 
( „ dull. .. ... . Bulimus 
g i Aperture toothless. Zua 
( „ denticulated .. ... ... Azeca 
H 2 
