158 
SPECIFIC 
PLATE XX. 
Fig. 1. Helix Scarahc^us. 
Shell ovate, two-edged, sub-umbilicate ; aper- 
ture toothed. 
Lister Conch. Tab. 577. Fig. 31. 
Specimen brown, variegated with pale spots, 
outer lip and teeth horny, white ; whorls conti- 
guous, double convex; aperture narrow, com- 
pressed, flexuous; each lip with three teeth. 
Inhabits Asia. 
Fig. 2. H. cornea. 
Shell umbilicate, flat; whorls four, round. 
Lister Conch. Tab. 197. Fig. 41. 
Specimen blackish horn-colour, longitudinally 
striate, reverse ; apex impressed. 
Inhabits the fresh waters of Europe and Coro- 
mandel. 
It is not easy to ascertain which is really the 
base, and which the apex of this shell ; but if it be 
umbilicate, it must also be reverse : this appears 
upon the whole to be the fact, and the specimen is 
therefore drawn placed upon the perforated part ; 
