1910.] osrnACODA fiiom Tanganyika. 745 



ratliei' tliin nnd pt'llucid, slightly iinecjunl, and liiudy liairv at 

 each extremity. Hiuface of shell pei'fectly smooth. 



Male (fig. (>) somewliat smaller than female, Ixit exhihitiug a 

 very similar shape of the shell. 



Length of shell $ U'41 mm., height ()"2i nun., width 0-17 mm. 



Remarks. — This form is allied to C. sinuata, but of rather 

 smaller size, and differs conspicuously in the nearly straight 

 ventral margin of the shell. 



Occurrence. — Some few specimens of this small Ostracod were 

 found in a sample from Tanganyika (138), taken 13/10/04 at 

 Sumbu (S.W. of lake). 



17. Cypridopsis monodonta, sp. n. (Plate LXX. figs. 7-9.) 



Specific Characters. — Male. Shell somewhat tumid ; seen laterally 

 (fig. 7) almost semicircular in outline, greatest height occurring 

 in the middle and nearly attaining two-thirds of the length, 

 anteiior extremity obliquely rounded, posterior blunted and some- 

 wdiat defiexed, dorsal margin boldly arched, ventral nearly 

 straight; seen dorsally (fig. 8) subovate in form, greatest width 

 exceeding half the length and occurring behind the middle, both 

 extremities somewhat blunted at the end, the posterior one being 

 the broader. Valves lather unequal, the left one overlapping the 

 right conspicuously along the whole anterior extremity, anterior 

 lip of this va;lve somewhat defiexed and having below a slight 

 sinus ; posterior lip armed at the lower corner with a snuiU 

 recurved dentiform process (fig. 9). Surface of shell smooth, 

 but rather densely haii-y at both extremities. 



Length of shell $ 0-36 mm., height 0-23 mm., width 0-20 mm. 



Remarks. — This is the smallest of all the Tanganyika Ostracoda, 

 and is, moreover, easily recognized by the short and tinnid shell 

 and by the peculiar dentiform process springing oft" from the 

 posterior corner of the left valve, a character whicli has given lise 

 to the specific name hei'e proposed. 



Occurrence. — A solitary male specimen of this form was found 

 in the same sample (138) from which 0. j^usilla was derived. 



18. Cypridopsls serrata, sp. n. (Plate LXX. figs. 10-12.) 

 Specific Characters. — Female. Shell moderately tumid; seen 



laterally (fig. 10) oblong reniform in shape, greatest height 

 occurring in the middle and about equalling half the length, both 

 extremities obliquely rounded and somewhat defiexed, dorsal 

 margin evenly curved, ventral conspicuously sinuated ; seen 

 dorsally (fig. 11) oblong-ovate in form, greatest width about 

 equalling two-fifths of the length and occurring behind the middle, 

 both extremities acuminate. Valves rather unequal, the right 

 being conspicuously overlapped by the left, both anteriorly and 

 po.steriorly ; each valve exhibiting at the posterior corner a row of 

 extremely delicate triangular serrations, four on I'ight, three on 

 left valve (fig. 12). Surface of shell smooth and linelv hairy 

 at both extremities. 



