Mr. Alber's Catalogue of Land and Fresh-water Shells. 35 



34. P. Vertigo, Drap. 



Vertigo pusilla, Mull. 

 Turbo Vertigo, Mont. 

 In moss ; rare. Causey Dean, Tanfield. 



A new genus was established by Muller for this species on the supposition that it had 

 only two tentacula. Draparnaud, however, says that it has four, the two inferior ones 

 being extremely short. In most of the species of this genus the upper tentacula are very 

 long in proportion to the size of the animal : the lower ones, on the contrary, are very 

 short, and not often protruded, so that, in a minute species like the present, they may be 

 very easily overlooked. 



Gen. HELIX. 



35. H. ericetorum, Linn. 



On banks and dry pastures near the sea ; not unfrequent. Most plentiful on a limestone 

 soil. 



36. H. virgata, Mont. 



H. variabilis, Drap. 

 In old quarries, on road sides, and sea banks, always on a limestone soil ; rather local. 

 Plentiful near Sunderland — Mr. J. Thornhill. 

 Three varieties occur : viz. 



White, with a single broad band of chocolate brown above, and smaller ones beneath. 

 Brownish white, with faint interrupted bands. 

 White, with a transparent white band. 



37. H. caperata, Mont. 



H. striata, Drap. 



On dry banks and in old quarries ; common : sometimes on the trunks of trees. Most 

 plentiful on limestone and near the sea. 



I have a variety from Marsden with the whorls elevated so high as to give it the ap- 

 pearance of a Trochus. 



38. H. rotundata, Mull, Drap. 



H. radiata, Mont. 

 Under stones ; common. 



I have two or three specimens of a beautiful greenish white variety, collected in this 

 neighbourhood. 



39. H. umhilicata, Mont. 



H. rupestris, Drap. 

 In old limestone quarries in exposed situations. Very plentiful in old quarries near 

 the sea at Marsden. 



40. m. pygmcBU, Drap. 



H. Kirbii, Shep. in Linn, Trans, v. xiv. p. 162. 



