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DESCRIPTION OF NA8SA SUBCONSTRIGTA, n.sp., FEOM 

 POET CANNING, MOUTH OF THE GANGES. 



By G. B. SowEEBY, F.L,S,, etc. 



Read Uth April, 1899. 



Testa elongata, antice abbreviato constricta, postice acuminata, 

 pallide fuscescens, ad apicem alba, papillaris ; spira acute pyramidalis, 

 sutura angusta, anfractus 7, primi (2^) Iseves, rotundati, sequentes 

 levissime convexi, superne leviter constricti, costis crassis laevibus 

 rotundatis instruct!, interstitiis spiraliter stiiati ; anfractus ultimus 

 convexiusoulus, semicostatus, basin versus spiraliter tenuiter con- 

 fertim liratus, prope aperturam costa crassa munitus ; apertura 

 parviuscula, intus albida, paucilirata; columella rectiuscula, alba, 

 extus tenuiter callosa, vix effusa, intus plicata; labrum externum 

 arcuatum, leviter reflexum ; canalis brevis, latiusculus, vix recurvus. 

 Long. 10, maj. diam. 4-5 mm. 



Nassa subconstricta, n.sp. 



Sal. — Port Canning, mouth of the Ganges (brackish water). 



A well-defined species, of which several specimens were found in 

 the collection of the late Colonel Mainwaring labelled '•' Port 

 Canning." It has the look of a brackish- water shell. The longi- 

 tudinal ribs of the spire are thick, rounded, and smooth, the spiral 

 striae in the interstices being quite conspicuous ; nearly half the body- 

 whorl is destitute of ribs, and in this portion of the shell the 

 constriction, a little below the suture, is more clearly noticeable than 

 where it is crossed by the ribs. In all the specimens there is a strong 

 rib, or varix, behind the mouth. 



