1910.] FRESHWATER CRUSTACEA FROM THE TRAXSVAAL. lf>7 



bristles ; the first two bristles, which are short and thick, bear 

 distally a number of small setaa ; the third is large and hairy ; 

 the fourth and fifth are smooth ; the sixth is short and serrated. 

 Small hairs are found to cover the ventral surface and other 

 parts of the appendage (PI. XIII. fig. 28). 



The fourth post-oral appendage : the third and fourth segments 

 are distinct : the arrangement of bristles and hairs resembles 

 that of C. gunningi. 



The fifth post-oral appendage : the bristle and curved seta 

 of the distal segment are comparatively long. 



Each ramus of the caudal furca bears along nearly the whole 

 of its inner edge a row of setas and distally the four characteristic 

 bristles. 



Remarks. — This species was found not uncommonly, together 

 with the other Ostracorls described, in the shallow littoral water 

 of Lake Ohrissie. 



Order OLADOCERA. 



Family Lynceid^e. 



Genus Leydigia Kurz. 



Leydigia trispinosa, sp. n. (PI. XVI. fig. 43.) 



Length P27 mm. ; height - 735 mm. This species resembles, 

 in the general shape of the body and character of the telson, 

 Leydigia acanthocercoides described by Lilljeborg (3) and figured 

 on pi. lxxi. fig. 4. The head is small. 



The posterior part of the carapace has the appearance of 

 having been " pulled out " in a ventro-posterior direction ; its 

 ventral margin is provided with a row of stout hairs. The two 

 large terminal spines of the telson are serrated ; each bears at 

 its base one small spine and a group of small hairs ; anterior 

 to these are eight pairs of fairly large stout spines ; at the base 

 of each arise two small ones of which the most internal is the 

 smaller ; the arrangement is therefore characteristically triple ; 

 in front of these spines, again, lie eight pairs of small spurs each 

 with its group of setae placed in an anterior position ; slightly 

 external to these, a row of fine setae, which runs nearly the whole 

 length of the body, is noticeable. 



Locality. Shallow littoral water of Lake Ohrissie. 



Genus Chydorus Leach. 

 Chydorus caroling, sp. n. (PL XVI. figs. 44 a, b.) 



Length -47 mm.; height -37 mm. Body rotund; posterior 

 angle distinct, without spine or process ; the ventral margin of 

 the shell has a fringe of spines ; the rostrum, which is long and 

 pointed, projects considerably beyond the end of both pairs of 

 antenna? ; no striations visible on the carapace ; the arrangement 

 of bristles on the telson is somewhat unusual. 



Found in same locality as preceding species. 



