G. ROBERTS I MOLLUSCA OF WRESSLE, 



313 



Succinea virescens. ' Shell thin, mouth expanded.' One specimen 

 found with putris. This was seen and identified by Mr. T. D. 

 A. Cockerell, of Chiswick. 



Succinea pfeifferi. Creeping on the surface of a muddy dyke with 

 the above. 



Succinea pfeifferi var. brevispirata Baud. With the above. 

 Zonites nitidulus. On the river bank. 

 Zonites cellarius. Wressle, under stones. 

 Zonites purus. Wressle. 



Helix aspersa. Frequent about cottage gardens, but apparently 



scarce elsewhere. 

 Helix nemoralis. Common near the river. 



Helix nemoralis var. alboJabiata. One specimen on the banks of 

 the Derwent. 



Helix nemoralis var. libellula 12 3 45 + bimarginata. 



Helix nemoralis var. petiveria. Common, with and without bands. 



Helix nemoralis var. trochoides Clessin. Alt. 16 mill., diam. 17 mill. 

 Remarkably trochiform. Shell yellow; band-formula 123OO. 



These varieties of nemoralis^ along with others, were obtained 

 on the artificial bank which runs along the river side from 

 Wressle towards Bubwith. The yellow shells with and without 

 bands predominate, and are very glossy with the epidermis 

 perfect to the apex. I saw no Helix hortensis. 



Helix arbustorum. Abundant on the river side. 



Helix arbustorum var. depressa Scholtz. Alt. 20, diam. 26 mill. 

 Wressle, J.B. 



Helix arbustorum var. conoidea ? 



Helix arbustorum var. trochoidalis Romaen. Alt. 20^ mill., diam. 

 i8£ mill. A variety new to Britain. One specimen of this 

 remarkable variety was picked up on the artificial bank in 1884, 

 but three more were obtained at the same place in July 1886. 



Helix arbustorum var. fusca. In a ditch near the railway station 

 in 1884, but none in 1886. Occurs also on the Derwent banks. 



Helix arbustorum var. fusca + roseolabiata (new var.). Lip 

 tinged with pink. Other specimens have the lip of a purplish 

 colour. 



Helix arbustorum var. cincta. One specimen in 1884; none in 

 1886. 



Helix arbustorum var. marmorata. One specimen, J.B. A large 

 percentage of the shells of both nemoralis and arbustorum that 

 occur on the artificial bank which borders the river, have a 

 pyramidal spire. The vegetation is of an ordinary kind. The 



Oct. 1886. 



