1910.] FRESHWATER. CRUSTACEA FROM THE TRANSVAAL. 163 



the right considerably larger than the left and armed with a long 

 terminal claw serrated on the inner side. This claw is borne by 

 the exopodite, which consists of three segments ; the distal one is 

 small, bearing, besides the long claw, a small protuberance or 

 knob on its outer margin ; the second segment, which has a short 

 spine terminally, is large ; the endopodite is two-jointed ; the 

 distal joint is much shorter than the proximal and is armed with 

 about four fine setae terminally: between the endopodite and 

 exopodite arises, apparently from the basipodite, a conspicuous 

 thorn. The basipodite itself is somewhat peculiar; it has a 

 rounded inner face bearing a double cushion, an inner part 

 furnished with a row of short curved spines, and an outer part 

 with a row of digitiform processes. Left limb : the distal basal 

 joint bears a bristle on its external surface and in addition an 

 exopodite, but no signs of a endopodite, unless a small knob on 

 its inner edge be taken as the remains of such. The structure of 

 the exopodite is not very clear ; but the following points have 

 been made out, namely : a long proximal curved claw serrated along 

 its inner margin, a cushion with serrated margin which is 

 produced externally and distally into a short curved spine, a second 

 distal cushion smaller than the proximal one, bearing two rows 

 of prickles. 



In the female this pair of limbs is in the main like that 

 of Diaptomus ; however, the first basal joint has no spines ; 

 the second basal joint is as thick as it is long ; both endopodite 

 and exopodite are present : the endopodite consists of one joint 

 only ; internally it; bears two very small spines some distance 

 apart, and terminally two bristles : the exopodite is two-jointed ; 

 the distal segment carries two spines, and is produced into a 

 serrated claw ; the middle spine has further a small bristle and 

 two or three minute hairs on its inner margin. 



The caudal furca are asymmetrical in both sexes, the left one 

 being longer in each case. Five stout plumose bristles are present, 

 and one small slender one which is smooth. 



Locality. "Very abundant in Lake Chrissie and in the pans 

 generally. 



Family Harpacticid^e. 



Genus Canthocamptus. 

 Canthocamptus ? 



The one specimen obtained, which was very small, was unfor- 

 tunately lost in attempting to macerate it. However, before 

 this happened, it had been determined that it belonged undoubtedly 

 to the genus Canthocampfais and closely resembled Canthocamptus 

 finni, as described and figured by Prof. G. C. Bourne (2a) from the 

 neighbourhood of Zanzibar. This specimen from Chrissie was a 

 female and was remarkable in having asymmetrical caudal styles ; 

 a text-figure of these is inserted, and it will be seen that the light 

 style is peculiarly bent and fashioned. This may be merely an 

 abnormality, but the process was certainly intact. In the general 



11* 



