1880.] G. Nevill — New Species of BraGlcisTi-water Mollmhs. 159 



XVI. — JSfeio Species of Braclcish-ioater MoUusJss, 

 By Geoffrey Nev^ill, C, M. Z. S. 



(Received November 1st ; — Read December 1880.) 



Subfamily BYTHINIINiE, Troschel [emend.]. 

 Gebiss der Sclinecken, I, 1857, as Group " Bytliiniae" ; emend. Stimpson, 1865, 

 and Clessin, Malak. Blat. 1880, as subfamily of the Eissoidae. 



StENOTHTRA WOODMASONIANA, n. S]). 



T. parva, imperforata, ovato-acwta, sol'ida, crassa, pallide viridula, 

 polita, nitida, {suh lenie) obsolete submalleata ; spira aculeiformis, suh- 

 concava, producta, apice peracutissimo ; anfr. 6, Imud convexi, uUimus 

 pertumidus, medio subatigulatiis, lasi applanatiis, antice ad aperturam 

 ahriipte et valide deflectus ; apertura percontracta, perfecte rotundata, 

 marginihus continuis, valide incrassatis. 



Long. 3-|-, diam. vix 2 mill. 



Hab. Port Canning. 



This interesting form is easily recognized by the very acute and con- 

 cavely-excavated spire, the subangulate last whorl, flattened round the 

 umbilical region ; it is not spirally pitted, as in most species of the 

 genus, but appears obsoletely malleated or indented under a powerful lens. 



This is one of Mr. Wood-Mason's interesting discoveries from the 

 still imperfectly explored brackish-water Sunderbunds (embouchure of the 

 rivers Hooghly, &c.). 



Type Indian Museum, Calcutta ; also in coll. Dohrn, Beddome, Theo- 

 bald, Blanford, and Hungerford. 



StENOTHYEA HUNGEEPOEDIAlirA, n. Sp. 



T. parva, imperforata, ovato-elonrjata, solidiusctda, viridula, vix nitida, 

 {suh lente) lineis impressis ac dense pmicticulat is confertimcingidata ; spira 

 paululum elongata, ovato-convexa, apice ohtuso, sutura profunda ac ohsoleta 

 marginata ; anfr. 4, convexi, ultimus coinpresse ovuliformis, antice sub- 

 ctpplanaius, valde descendens ; apertura perpusilla, subohliqiie rotundato- 

 ovata, superne levifer angulata, sulco profwndiori ab anfractK, ventrali 

 separata, peristomate obtuso. 



Long. 21, diam. 1} mill. 



Hab. Andaman Islands. 

 21 



