756 



ritoF. i;. (». SAKS ox 

 'I'tilile of Di-ilriliid'tdii. 



fM.-.y3, 



Niiims (if Siii'cit's. 



,r- . ■ Other 



.,, ■\ ' Tj Victoria , ,. 



laiiLiiinvika. Is'yasa. »r parts ot 



I ' Africa. 



of the genera here recoi-ded are espeoially riclily represented in 

 Lake Tanganyika, viz. Pai-acypria and Ci/pridopsis. Of the tirst- 

 named genns no less tlian twelve different sjiecies have been 

 determined, all exelusively peculiar to that lake and exhibiting a 

 remarkable specialisation as reganls the external appearance. 

 The ty})e of this genus, P. tenuis G. 0. S., as mentioned aI)ove, 

 WHS found in the very sjiine brackish-water lagoon on the Chatham 

 Islantls from wliich the tyjie of the Co[)epod genus Svhizopera 

 was derived. The suggestions set forth in my previous ])aper 

 about the prol)able origin of the several species of the last-name I 

 genus occurring in Tanganyika may therefore also :ipply to those 

 of the Ostracod genus hei-e uu<ler question. As regards the otlier 

 genus, Ciipridnpsis, it may be noted here that only two of the 

 ten species determined exhibit all the characteristic featiu-es of 

 that genus, and these two species do not occm- in Tanganyika, one 

 of them, C. cunnhif/toni, being derived from Lake Nyasa, the 

 other, C. ii'ibha, fi-om A'ictoria Nyanza. The remaining eight 

 species diHei- Mimewliat in the .-shape of the >liell and the mutual 



