748 Description of Land and Fresh-water Shells [Nov. 



ovata, intus albida, fasciis quibusdam castaneis ornata ; labro intua 

 denticulate 



This species resembles so closely the figure given in Griffith's 

 Cuvier, PL 14, f. 3, as Melania conica of Gray, that I am unwilling 

 to describe it as new, in the absence of a specific character of that 

 shell. Gray's figure, however, does not exhibit the obsolete sulcations 

 of the shell under review, — an omission which may be attributed to the 

 brown incrustation with which they are ordinarily obscured, nor the 

 smoothed denticulations which ornament the interior margin of the 

 right lip in our shell. Should it eventually prove to be distinct, it 

 may be named M. denticulata from this character, which is also pos- 

 sessed in a minor degree by M. Stephanas. The spire is eroded in 

 all the specimens which I have examined. Length one inch. 



34. Neritina depressa. Testa solida, sub-convoluta transverse 

 ovata, gibbosa, olivacea, longitudinaliter purpureo-fusco late strigata, 

 strigis versus apicem angulato-flexuosis ; spira depressa ; anfractibus 

 sub-binis ; peritremate integro acuto, sub-orbiculari ; septo calloso 

 magno ; apertura parva, lunata, aurantia ; labio sub-recto, medio emar- 

 ginato, ibi denticulate 



Greatest transverse diameter 0.8 inch. The peritreme which sur- 

 rounds the aperture and shelving callus is nearly free, and occupies 

 nearly the whole face of the shell. All within it, including the sep- 

 tum as well as the aperture, is usually of a dull orange colour. When 

 weathered the shell is whitish, with pink bands and zig-zag lines ; the 

 denticulations of the inner lip are occasionally obsolete. The indivi- 

 duals in the Society's collection are probably from the Sundarban 

 rivers, as the species is common, adhering to wooden piles and brick- 

 work in the Hughli at Calcutta, as well as in waters which have 

 periodical communication with it. The following species is so nearly 

 allied to iV*. depressa that I shall describe it here for the purpose of 

 instituting a comparison and pointing out the distinctive characters, 

 although no example of it occurs in the collection. 



35. Neritina cornucopia. Testa solidiuscula, convolute, subsym- 

 metrica, transverse ovato-acuta, gibbosa, pallide virente, punctis mi- 

 nimis nigris, interdum confluentibus, lineis longitudinalibus dispo- 

 sals ornata ; spora valde depressa ; anfractu pone callum compresso, 

 sub-mediano, minime obliquo ; peritremate acuto, libero, ovato, pene 

 totam testam circumcludente ; callo magno ingrescente ; apertura 

 lunata mediocri ; labio recto tota longitudine denticulato, medio 

 emarginato. 



Greatest transverse breadth 0.7 inch. At the first glance this shell 

 would probably be mistaken for the last described species, from 



