HYDRACIINIDAE FOUND IN THE EAST AFRICAN LAKES. Ill 



not at all unusual for members of this genus to have a number 

 of papillae projecting beyond the marginal line of the body. 

 lY. imibonata Koen, has three on each side, but they are directly 

 on the marginal line and not set a little way on the dorsal 

 surface, as we find in this species ; although Koenike's species 

 has three papillae on each side, it has not the two we find on the 

 posterior margin, or rather four, for there are two on each side 

 of the median line in X. 2)apilhsc(. 



Unionicula figuralis Koen. 

 Two females of this species. 



Mideopsis minuta sp. nov. (PI. 5, Figs. 8, 9.) 



This is a very small species, and is probably a male. The 

 unusual point about it is that the genital area has four acetabula 

 on each side of the genital fissure. This appears to be a very 

 unusual number among the water-mites. The length of this 

 i>pecies is only 0*48 mm. The colour is well preserved, the 

 triangular shaded patch in the anterior region being a Prussian 

 blue ; this was, in fact, the only mite in the collection in which 

 the colour had been preserved. But this is usual with all the 

 hard-skinned forms. There was only one specimen in the 

 collection. 



Hygrobates edentipalpis sp. nov. (PI. 5, Figs. 3-7.) 



Female : Length, 0*72 mm. ; breadth, 0'60 mm. Well rounded 

 on anterior margin. It differs very little from the other members 

 of this genus except in the palpi. The palpi of all the species 

 of this genus, as far as I know, are more or less covered with 

 teeth on the inner edije of the second and third sesfments. On 

 the palpi of this mite I can find no such teeth, so I propose 

 to caU it I/i/r/rohafes edentijxdpis. Several females and males 

 were found in the collection. The females were all full of ova; 

 some had three, others had four eggs. The male is a little 



