6o Mr. James Cosmo Melvill on 



unsolved and difficult the nomenclature of these extremely 

 beautiful but very microscopic genera and species. 



In O. tornata the transverse ribs are three in number, 

 two below the deeply-channelled sutures, followed by a 

 similar deep groove, and then a third transverse costa, just 

 above the suture of the next whorl. 



Three specimens obtained in shell sand. Very rare. 



Pyrgulina callista, sp. 710V. (PL I, f. 13). 



P. testd delicatitld, subpelhicidd, attemiato-fusiformi, an- 

 fractibtts septem^ ad siituras profiuide angidato-canaliculatis^ 

 longitudinaliter-costis regtdaribns suboblique decoratis, inter- 

 stitiis l(Evibus, ultimo anfractii infra suturas iransversini 

 fortiter Jinilirato, ad dorsiun bino lirarum ordine, aperturd 

 ovato-oblongd, labro qiiadratulo, ad margiiiem columellareni 

 uniplicato. 



Long. 4 mill. 



Lat. no „ 



Hab. Bombay i^Abercroinbie). 



One of the most exquisite little shells, so far as sculpture 

 is concerned, that it is possible to imagine. The shell is 

 seven-whorled, deeply angularly channelled at the sutures, 

 with raised transverse border at either end of the whorl, 

 the borders joined by slightly oblique lirae, smooth at the 

 interstices, the last whorl having a conspicuous angular 

 transverse border line, and at the back of the shell another 

 parallel to this, the lip is subquadrate, and the columellar 

 margin with a very conspicuous plait. 



Two or three specimens in shell sand. Very rare. 



Rissoina (Zebina) applanata, sp, nov. (PI. I, f. 16). 

 R. testd alba, nitidd, sublcBvi,fusifor7ni,apiceobiiiso,atz- 



