158 SPECIFIC 



PLATE XX. 



Fig. 1. Helix Scarabans. 



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 hp 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; 



