34 G. O. Sars. 



the middle, dorsal margin gibbously arched, ventral but 

 very slightly sinuated, both extremities obliquely rounded 

 and nearly equal; — seen dorsally, almost globular in form, 

 greatest width considerably exceeding the height, both ex- 

 tremities obtuse. Valves but slightly unequal, smooth, with 

 only small and scattered hairs at each extremity. Caudal 

 rami exhibiting the rudimentary structure characteristic of 

 the genus. 



Colour. — Shell of a light yellowish green colour, with 

 a number of comparative!}^ small dark patches, partly forming 

 on each side 3 interrupted transversal bands.- 



Length of shell 0-46 m"\ height 0-33 ii^™, width 0-35 "^n\ 



Remarks. — This form at the first sight somewhat 

 resembles the Australian species Pionocypris globulus G. O. 

 Sars. It is, however, a true Cypridopsis, as shown by the 

 structure of the caudal rami. 



Occurrence. — Several specimens of this form were 

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

 matra. It was also found occasionally in the sample taken 

 by Mr. Iversen. 



13. Cypridopsis adusta, G. O. Sars, n. sp. 



(PI. IV, figs. 4, 4 a— b). 

 Specific Characters. — Female. Shell rather tumid, 

 seen laterally, oval triangular in form, greatest height some- 

 what exceeding | of the length and occurring about in the 

 middle, dorsal margin well arched, ventral nearly straight, 

 anterior extremity obliquely rounded, posterior somewhat 

 narrower and obtuse at the tip ; — seen dorsally, broadly 

 ovate in form, greatest width about equalling the height, 



