32 Melvill, Molluscan Fauna of the Arabian Sea, etc. 



postice fere recto^ antice inultum declivi^ superfice albida 

 concentrice irregulariter lirata, liris apiid medium antice et 

 postice oblique gramdoso-undosis^ intus albay linea palliali 

 parum sinuosa. 



Alt. 7, lat 8*50 mm. 



Hab. Indian Ocean ; 33 fathoms, long. 26'' 10' N., lat. 

 52^50' E., mud, and coral rock. 



A dwarf Circe^ in size resembling the British and 

 Mediterranean C. minima L. It is white, obliquely 

 orbicular, the umbones slightly attenuate, prominent, the 

 dorsal margin straightish posteriorly, much declining 

 anteriorly, the shell being unequally concentrically lirated, 

 the lirsB ornamented with oblique nodules tending regu- 

 larly posteriorly and anteriorly, ceasing beyond the middle, 

 while the shell is slightly shining. Within white, the 

 pallial line hardly sinuous. 



DiPLODONTA GENETHLIA, Sp. nov, 

 (PI. 2, f II). 



D. testa oblique rotunda^ ventricosa^ nitida, Icevi^ indis- 

 tincte concentrice striata, straminea vel cinereo-alba, umboni- 

 bus approximatiSy incurvis, prominulisy dorsaliter utrimque 

 rapide declivi, postice rotunda, antice a medio marginem ad 

 ventralem tri- vel quadri-plicata, plicis obtusis, inconspicuis, 

 intus albescentey cardine in utraque valva bidentato, dentibus 

 incequalibus. 



Alt. 7, lat. 7-50, diam. 5 mm. 



Hab. Gais (or Kais) Island, 7 to 10 fathoms ; also 

 Muscat, 10 fathoms, Persian Gulf 



An obliquely rounded shell, straw coloured or olivaceous 

 or ashy white, shining, concentrically striate, umbones 

 approximate, prominent, valves extremely ventricose and 

 tumid, posteriorly round, anteriorly three- or four-plaited, 

 the plaits commencing below the centre of the shell to 

 the ventral margin. 



