90 



tinually in motion, and exude a liquor which lubricates the shell, 

 supplying, apparently, that fine gloss which is obsen'able in aU re- 

 cent specimens. The fluid poured out from the orifice at the base 

 of the caudal horn-like appendage is of a greenish colour ; it exudes 

 when the animal is irritated, and at such times the caudal appen- 

 dage is directed towards the exciting object in such a manner as to 

 give to the animal a threatening aspect. 



Of several specimens brought to England by Mr. Benson in 1832, 

 one survived from December 1831, when it was captured in India, 

 until the summer of 1833. 



Another Shell particularly noticed by Mr. Benson is the type of 

 a new genus, allied to Cyclostoma, which he has described \mder 

 the name of Pterocyclos in the first No. of the ' Journal of the Asi- 

 atic Society of Calcutta.' Mr. Benson has ascertained, by the in- 

 spection of specimens in the collection of Mr. G. B. Sowerby, that 

 the Cycl. bilahiatum of the latter is the same shell at a more advanced 

 period of growth ; when, in addition to the notch and overhanging 

 wing at the upper part of the aperture, the peristome becomes 

 thickened and sinuated. The Cycl. Petiverianum, Gray, exhibits 

 an approach to Pterocyclos in the crude formation of a wing at the 

 upper part of the right lip. 



A species of Assiminiu, Leach, obtained at Barrackpore, has the 

 shell ovate-conical, narrowly umbilicated, varying infinitely in co- 

 lour, and generally banded with red, white, and glaucous; the 

 aperture is entire, oblong-oval, angular at the upper part. The head 

 has only two short, thick, subcylindrical tentacula, with the perci- 

 pient points placed at their summits. The snout is like that of 

 Paludina, transversely corrugated, and bilobed or rather emarginate 

 at the middle of the extremity ; the lobes rounded. The mantle is 

 free ; the branchial cavity open. The foot has a spiral horny oper- 

 culum, angular at the upper end. 



Specimens of this Assiminia were preserved alive in a glass, reple- 

 nished occasionally with fresh or salt Avater, until after the vessel 

 in which Mr. Benson returned to England had passed St. Helena. 



A Snail obtained near Sicrigali and the river Jellinghy, one of 

 the mouths of the Ganges, is thus characterized by Mr. Benson : 



Helix interrupta. Hel. testd sinistrorsd, orbiciilato-convexd, in- 

 fra tutnidd, umbilicatd, ad peripheriam obtuse angulatd, longitu- 

 dinaliter confertissirrie striata, supra striis interruptis, fasciis 

 transversalibus dispositis; spird apice obtusd; peritremate tenui, 

 acuta. 



Animal. Tentacula duo superiora elongata capitulis tumidis puncta 

 percipientia gerentibus, duo inferiora capitulis parvis tumidis. 

 Pes elongatus, compressus, marginatus, suprcL granulatus, aper- 

 turd terminali anum et mcmbrum carnosum mucorem emittens 

 continente. 



In this latter character, that of the excrement being voided from 



