from the Mauritius. 179 



of distribution, extending even into the European seas. Some 

 additional species from the same locality will be described in a 

 future Number of ^ Les Fonds de la Mer.' 



List of Species, 



Pontocypris attenuata, nov. sp. 



Davisoni, nov. sp. 



Macrocypris maculata, Brady. 

 Cythere demissa, nov. sp. 



plana, nov. sp. 



fumata, nov. sp. 



Hodgii, Brady. 



Darwinii, Brady*. 



Cythere hamigera, nov. sp. 



bispinosa, nov. sp. 



convoluta, nov. sp. 



Cytheridea punctillata, Brady. 



spinulosa, nov, sp. 



Loxoconcha Lilljeborgii, nov. sp. 

 Xestoleberis margaritea, Bt-ady. 



Pontocypris attenuata^ nov. sp. (Plate IV. figs. 11-14.) 



Carapace, as seen from the side, subtriangular or siliquose, 

 highest in front of the middle, and tapering to a point be- 

 hind ; greatest height scarcely equalling half the length : 

 anterior extremity broadly rounded ; posterior subacutely 

 pointed : superior margin obtusely angular at its highest 

 point, from which it slopes steeply backwards with a gentle 

 curve ; inferior slightly sinuated about the middle : outline, 

 as seen from above, compressed, somewhat clavate, widest 

 at the anterior third, rounded and slightly mucronate in 

 front, pointed behind ; greatest width equal to rather more 

 than a third of the length. End view oval, widest in the 

 middle. Surface of the shell smooth, slightly punctate, and 

 clothed with numerous exceedingly short and fine hairs. 

 Colour pale yellowish brown. Length -3^ inch. Animal 

 unknown. 



This pretty species approaches very closely to the European 

 P. mytiloidesj but is paler in colour, less distinctly pubescent, 

 has a more shining surface, a more angular dorsal margin, and 

 is also destitute of serratures at the posterior extremity. 



Pontocypris Davisoni^ nov. sp. (Plate XIII. figs. 9, 10.) 



Carapace of the female (?) somewhat tumid, as seen from the 

 side subreniform, highest in the middle ; greatest height 

 fully equal to half the length ; rounded in front : posterior 

 extremity rounded off* below, scarcely angular ; superior 

 margin boldly arched, highest in the middle, inferior sinuated 

 in front of the middle. Seen from above, the outline is 

 ovate, widest near the middle, pointed in front, rounded be- 

 hind ; width much less than the height. The surface of the 

 shell is granular or very finely punctate, and quite devoid 



* Described in ' Les Fonds de la Mer.' 



