1910.] OSTUAC'ODA FROM TAXGAXYIKA. 737 



6. Paracypria subaxgulata, sj). n. (Plate LXVI. figs. 7-11.) 



Sfecific Characters. — Female. Shell somewhat less compressed 

 than in the preceding species; seen laterall}- (fig. 7) broadly oval 

 in form, greatest height occurring nearly in the middle and 

 considerably exceeding half the length, anterior extremity 

 obliquely rounded and subangular below, posterior scai-cely 

 narrower and terminating in a slightly deilexel obtuse corner, 

 dorsal margin forming a rather even curve, ventral almost 

 straight ; seen dorsally (fig. 8) oblong-oval in shape, greatest 

 width occuiring behind the middle and almost attaining half 

 the length, both extremities somewhat blunted at the end. 

 Yalves less pellucid than in the preceding species and very 

 unequal, the right one being considerably overlapped by the left 

 both in front and behind ; anterior lip of right valve simple and 

 evenly curved, that of left valve (lig. 10) forming below an 

 abrupt angular bend and exhibiting inside the hyaline border a 

 thickened zone crossed by a number of somewhat irregular 

 branching grooves. Surface of shell smooth and very finely 

 hairy at each extremity. Caudal rami (fig. 11) considerably 

 curved ; claws of moderate size and slightly unequal, the distal 

 one about half the length of the ramus ; dorsal seta slender and 

 elongated. Ends of ovarial tubes in this and the two preceding 

 species deflexed. 



Male (fig. 9) a little smaller than female and having the shell 

 somewhat less vaulted above. 



Length of shell $ 0-86 mm., height 0"48 mm., width 0"39 mm. 



Remarks. — This form is undoubtedly nearly related to the two 

 preceding species, but is of considerably larger size than either 

 of them, and is, moreover, easily recognized by the moi'e vaulted 

 shell and especially by the peculiar angular appearance of the 

 anterior exti'emity caused by the projecting lip of the left 

 valve. 



Occurrence. — Only three specimens of this form, two females 

 and one male, have come under my notice. They were found in 

 a sample from Tanganyika (53) taken 9/8/04 at JSTiamkolo (S. end 

 of lake). 



7. Paracypria rexiformis, sp. n. (Plate LXVII. figs. 1-4.) 



Specific Characters. — Female. Shell not much compressed ; seen 

 laterally (fig. 1) oblong reniform in shape, greatest height occur- 

 ring in the middle and not nearly attaining half the length, 

 anterior extremity evenly rounded, posterior somewhat nairower 

 and obtuse at the end, not deflexed, dorsal margin forming a 

 quite even curve throughout, ventral one rather deeply sinuated 

 in the middle; seen dorsally (fig. 2) oblong fusiform in shape, 

 greatest width exceeding one-third of the length and occurring 

 in the middle, both extremities acuminate. Valves very thin 

 and pellucid, only slightly unequal ; left valve, however, as usual, 

 overlapping the light a little along the anterior extremity ; lips 



