Mr. "W. T. Blanford on Cremnobates Syhadrensls. 185 



hates which I found in motion were living on the wet rock in a 

 place where a small stream trickled down the surface of a steep 

 rocky ledge ; everywhere else the shells were firmly attached to 

 the rock in crevices and hollows. I am therefore, I think, jus- 

 tified in considering this form as rather an amphibious than a 

 true land-shell ; and this view is confirmed by the circumstance 

 that when placed in a glass of water, the animals sometimes 

 crawl out and creep about the glass, but quite as frequently 

 remain beneath the water or just at its surface. Many Indian 

 species of the genus Littorina itself are equally amphibious in 

 their habits, always keeping at the limit of the advancing tide 

 as long as possible, and, in some cases, inhabiting rocks far 

 above the extent of the spray in ordinary tides and fair weather. 

 I have thus met with L. Malaccana, Phil., in crevices of rocks 

 several feet above high-water mark of ordinary tides, on the 

 coast of Burma, in a place where they must frequently have re- 

 mained many days, if not weeks, without being wetted by the 

 sea. 



I have carefully examined several individuals of Cremnobates 

 without being able to detect any trace of gills, while the large 

 vascular sac at the back of the neck exactly resembles that in 

 the operculated land-shells*. The mantle-margin is free, and 

 the sexes distinct. The lingual ribbon is very long ; one from 

 a large specimen measured f inch (17 mill.) ; the teeth are 7- 

 ranked, but differ in form from those of Cyclostomaceous genera. 

 The amphibious habits of the animal, the short foot, and the 

 olive-green epidermis, so characteristic of fresh-water shells, in- 

 duce me to place it in the vicinity of Lithoglyphus. Cremno- 

 bates is well distinguished from that genus by its perforation, 

 sculpture, and testaceous operculum, resembling in the two for- 

 mer characters the genus Fossar, species of which abound on 

 parts of the Indian coast. One of the common Indian species of 

 Littorina also, L. ventricosa, Phil., bears a considerable general 

 resemblance to the form now described, and has a somewhat simi- 

 lar though less strongly marked sculpture. Young specimens 

 of Cremnobates are frequently imperforate, the umbilicus being 

 entirely covered by the columellar margin of the peristome. 



Should my opinion as to the pulmoniferous character of this 

 genus be confirmed, its place amongst the families of opercu- 

 lated land-shells will be difficult to determine. Its subulate 

 tentacles and undivided foot distinguish it from Cyclostoma, its 

 paucispiral and excentrically nucleated operculum from Cyclopho' 



* My own experience in MoUuscan anatomy is too small for me to state 

 positively that no gills exist, until my observations have been confirmed 

 by a better observer. 



Ann. ^ Mag. N. Hist. Ser. 3. Vol. xii. 13 



