96 A'ALVATID.i:. — PILID.E. 



throu2;hout Europe, Siberia, and Asia Minor, is talven from Reeve's 



•' Laud and Freshwater MoUusks indigenous to the 



British Isles " : — 



Shell : somewhat globosely heliciform, deeply narrowly um- 

 bilicated, pale straw-colour, semitransparent but solid ; whoi'l.s 

 four and a halB to five, depressed at the apex, longitudinally 

 densely finely striated, spirally faintly ridged, ridges sometimes 

 obsolete ; aperture somewhat pyriformly rounded. 



" Valvdta piseinalis is almost milk-white, showing its bright 

 blue-black eyes very conspicuously on the inner base of each 

 tentacle." 



It is recorded from Kashmir. 



187. Valvata (?) microscopica, G. Nevlll. 



Valodta (?) microscopica, G. Nevill, Cat. Moll., Fasc. E, 1877, & 

 Hand List, pt. 2, p. 17. 



Original description : — Shell exceedingly minute, orbicular, 

 moderately thin, depressed, and discoidal ; whorls four, moderate, 

 convex, with distinct suture, the last whorl increasing rapidly ; 

 the shell, both above and below, rugosely and distinctly spirally 

 striated, deeply umbilicated, with rounded and proportionately 

 rather large aperture : the specimens were coated with some thick 

 black deposit ; when cleaned the shell presents a brownish-red 

 appearance ; the operculum examined under the microscope is 

 horny and circular, of comparatively rather thick substance ; it 

 appears to be multispiral, but we were not able to make out the 

 structure quite satisfactorily. 



Diam. 1"0 mm. 



Hub. Port Canning, in brackish water. 



Family PILID^E [=Amptcllanidct']. 



Subfamily PILIN.^. 



Shell globose, large, holostome, with calcareous operculum. 



Genus PILA. 



nia, Bolten, Mas. Bolten. 1798. 



Ampullaria, Lamarck, Mem. Soc. Hist. Nat. Paris, 1790, p. 76. 



TvPE, Heli.c ampullacea, Linn. ; Malaj^sia. 



Range. S.E. Asia ; C. Africa. 



Shell turbinate, globose, with little exserted si)ire ; aperture 

 oblong, oval; labrum arched, simple, occasionally reflexed ; 

 operculum calcareous. 



