MR. H. F. BLANFORD'S REVIEW OF 



from Peradinia, near Kandy, the upper whorls are in certain of the specimens somewhat 

 exserted, but only to a slight degree. In the more elongate forms the slight flattening 

 and angulation of the upper part of the whorls which characterize the more glo 

 specimens tend to become obsolete. 



Coloured specimens, which are almost always young shells, have sometimes two, some 



times three bands. 



The operculum of this species is characterized by its more pyriform shape than that 

 Philopotamis mlcata, and by the nucleus being further from the margin. The position 

 of the latter is somewhat variable (see fig. 12 a, b). 



Pa/udomus olicaceus, Reeve, from Sumatra, bears much resemblance to this species ; 

 but, in the absence of its operculum, no safe conclusion can be drawn. 



PHILOPOTAMIS NIGRICANS, B/eeve. (PI. XXVII. figs. 3 a-e, 15 , 6.) 



Shell of type-form, thick, elevately conical (apical whorls almost invariably eroded), 

 ornamented with close-set granular striae, those near the suture more developed than 

 the rest. Colour of epidermis dark citrine to black. The shell painted with numerous 

 wavy brown bands, generally visible only in the interior, and sometimes obsolete near the 

 aperture. Spire, when perfect, acutely conical ; whorls about six, rarely more than three 

 remaining in eroded shells, flattened, with shallow sutures. Last whorl more or less 

 angulate at the periphery, obliquely flattened beneath. Aperture obliquely ovate, 

 pointed above. Peristome white or greyish white, callous: outer lip sharp, even: 

 columella slightly arcuated anteriorly. Operculum paucispiral : nucleus rather large, 

 transversely central, and at from Jth to fths of the height. 



Var. a. (The only specimens found, not fully grown.) Shell in form as above, uneroded, 

 smooth, with one or two strong striae only near the suture. Epidermis transparent, 

 citrine, with the markings of the shell distinctly visible through it. 



? Var. /3. Form of shell as above, but more elongate. Shell'smooth, colourless or with 

 the bands broken up into a series of square dots. Last whorl elongate, the angulation 

 nearly or quite obsolete (PL XXVII. fig. 3 e). 



This species is more nearly allied to Melania, both in form and in the structure of the 

 operculum, than any of its allies. From P. decussata, the only congener to which it 

 bears any near resemblance, it is distinguished by its more conical form, the angularity 

 of the last whorl, and the character of the marking, as well as, in the majority of speci- 

 mens, by the granular surface, which, so far as I have seen, is peculiar to this species. 



The type-forms and the var. a. were collected by myself in large numbers (associated 

 with Tanalia violacea) in some small mountain streams near Huckgalle, at an elevation 

 of 5000 feet. With regard to var. |3, 1 am in some doubt whether it really belongs to this 

 species, notwithstanding that var. a, and a single colourless specimen of the normal form 

 given me by Mr. Cuming, seem to link it with the type. The only specimens I have 

 seen were in Mr. Cuming's collection, where they were erroneously referred to Palndomns 

 palustris, and none of the specimens contained opercula. In the absence, however, of 

 any adverse evidence, I provisionally regard this as a variety of P. nigricans. 



