89. 



The specimens from which the above characters have been taken 

 appear to give the most perfectly regular form of the species. There 

 are other varieties from Payta and the Isle of Muerte. — G. B. S. 



A collection of land a.nd fresh-water Shells, formed in the Gangetic 

 Provinces of India by W. H. Benson, Esq., of the Bengal Civil 

 Service, and presented by that gentleman to the Society, vi^as ex- 

 hibited. It comprised forty species, and was accompanied by a de- 

 scriptive list prepared by the donor, and also by detailed notices of 

 some of the more interesting among them. These notices were 

 read : they are intended by Mr. Benson for publication in the forth- 

 coming No. of the ' Zoological Journal.' 



From the time that he first became acquainted with the animal of 

 a Shell resembling in all respects, except in its superior size, the 

 European Helix lucida, Drap., Mr. Benson regarded it as the type 

 of a new genus of Helicida intermediate between Stenopus, Guild., 

 and HelicoUmax, Fer. He had prepared a paper on this genus, for 

 which he intended to propose the name of Tanychlamys ; he finds, 

 however, that Mr. Gray has recently described (page 58) the same 

 genus under the name of Nanina. The generic characters observed 

 by Mr. Benson are as follows : 



Nanina, Gray. 



Tes^a heliciformis, umbilicata; peritremate acuto, non reflexo. 



Animal cito repens. Corpus reticulosum, elongatum. Pallium 

 amplum, foramine communi magno perforatum, peritrema amplex- 

 ans ; processubus duobus transverse rugosis (quasi articulatis) 

 omni latere mobilibus instructum, unico prope testae apertures 

 angulum superiorem exoriente, altero apud peripheriam testae. 

 Os anticum inter tentacula inferiora hians ; labia radiato-plicata. 

 Tentacula saperiora elongata, punctum percipiens tumore oblongo 

 situm gerentia. Penis prsegrandis ; antrum cervicis elongatum la- 

 tere dextro et prope tentacula situm. Solea complanata pedis latera 

 sequans. Cauda tentaculata; tentaculum subretractile, glandula ad 

 basin posita humorem yiscidum (animale attrectato) exsudante. 



Mr. Benson describes particularly the habits of the species ob- 

 served by him, which he first discovered living at Banda in Bundel- 

 kund on the prone surface of a rock. The animal carries the shell 

 horizontally or nearly so ; is quick in its motions ; and, like Heli- 

 coUmax, it crawls the faster when disturbed, instead of retracting its 

 tentacula like the Snails in general. In damp weather it is rarely re- 

 tracted within its sheU, the foot being so much swelled by the ab- 

 sorption of moisture that if it is suddenly thrown into boiling water 

 the attempt to withdraw into the shell invariably causes a fracture 

 of the aperture. In dry weather the foot is retracted, and the aper- 

 ture is then covered by a whitish false operculum similar to that of 

 other Helicidce, The two elongated processes of the mantle are con- 



