32 G. O. Sars. 



Occurrence. — Some few specimens of this form devel- 

 oped in one of my aquaria prepared with mud from Su- 

 matra, 2 of which were secured for further examination. 

 They were both of the female sex and apparently fully 

 grown, to judge from the well developed ovarial tubes. 



9. Cypria cremilata, G. O. Sars, n. sp. 



(PI. IV, figs. 2, 2 a— b). 



Specific Characters. — Female. Shell much com- 

 pressed, seen laterally, rounded oval in form, greatest height 

 about equalling | of the length and occurring behind the 

 middle, dorsal margin well arched and sloping gently in 

 front, more abruptly behind, ventral somewhat convex in 

 the middle, anterior extremity narrowly rounded and some- 

 what deflexed, posterior much broader and bluntly trun- 

 cated; — seen dorsally, narrow oblong, greatest width not 

 attaining half the length, anterior extremity narrower than 

 posterior. Valves rather unequal, left one overlapping the 

 right both in front and behind, as also somewhat ventrally, 

 whereas it is overlapped by the right for some extent dors- 

 ally, anterior edge of right valve minutely tubercular; sur- 

 face smooth, clothed at each extremity by scattered delicate 

 hairs. Eye very large and conspicuous. Caudal rami slightly 

 arcuate and gradually tapering distally, apical claws com- 

 paratively short, but rather strong and slightly curved, the 

 outer one not attaining half the length of the ramus, seta 

 of dorsal edge rather slender and recurved, occurring about 

 in the middle, apical seta very small. 



Colour. — Shell rather pellucid, of a light yellowish hue, 

 without any pigmentary dots. 



