Burmese Species of Assim'mesi. 383 



Although doubtless locally abundant, this little mollusk does 

 not occur so generally on the shores of Bombay Island as the 

 next two species; and Mr. Fairbank informs me that, in a recent 

 search, he failed to find it. It may be distinguished from most 

 others of the genus by its rounded, gradually increasing whorls, 

 and, in general, by its distinct perforation, which is only com- 

 pletely covered by the columellar margin of the aperture in two 

 specimens out of fourteen which I have before me. 



It is manifest that the name of this species was published be- 

 fore Dr. Pfeiffer^s Hydrocena cornea^ from Borneo, described in 

 ' Proc. Zool. Soc' for 1854, and shown by Dr. E. von Martens 

 to be an Assiminea. The Number XVIII. of the ^ Journal of the 

 Bombay Branch, Koyal Asiatic Society,' in which Dr. Leith's 

 description appeared, was, as I have already mentioned, circu- 

 lated to the members of the Society in July 1853. The Borneo 

 species will therefore require to be named afresh — a task which, 

 as I am unacquainted with it, I would prefer leaving to Dr. Pfeiffer. 



Assiminea subconica, Leith, sp. (Fig. 2.) 

 A. testa imperforata, subrimata, ovato-comca, solidula, pallida au- 

 rantiaca, glabra, nitidula. Spira conica, lateribus vix convexis, 

 apice acute, sutura parum impressa, non marginata. Anfr. 7, 

 subplani, sensim accrescentes, ultimus subtus rotundatus. Aper- 

 tura spira multo brevier, parum ebliqua, superne angulata ; peri- 

 stoma rectum, margine externe tenui, celumellari vix incrassato 

 expansulo. 

 Operculum praecedentis. 

 Long. 4, diam. 2^, apert. long, l^ millim. 

 Hab. Same as that of A. cornea. 



This small species has more the form of A. Francisci and its 

 allies. The animal was found by Dr. Leith to be similar in 

 colour and form to that of ^. cornea. Mr. Fairbank informs me 

 that he has found A. subconica at a rather lower level than A. 

 cornea, on the mud, near high-water mark. 



The colour of the shells in this and other species of Assiminea 

 tends to fade after a time ; and some of my specimens are rather 

 yellowish horny than orange. 



Assiminea marginata, Leith, sp. (Fig. 3.) 

 A. testa imperforata, subrimata, ovate-conoidea, solidula, olivacea, 

 oleose-micante, striatula, lineis minutissimis spiralibus sub lento 

 signata. Spira conica, lateribus convexis, apice acuto, sutura 

 parum profunda, linea impressa aliquando obsoleta late marginata. 

 Anfr. 6, supra lente, infra celerius accrescentes, parum convexi ; 

 ultimus magnus, subtus glebosus. Apcrtura spiram paulo supe- 

 rans, parum ebliqua, supra acute angulata ; j)eristoma rectum, 

 margine externe tenui, celumellari incrassato expanse. 

 Operculum simile ei A. cornece. 

 Long. 4^, diam. 3, apert. long. 2|, lat. \\ millim. 



