158 TOE HON. PAUL A. METHUEN ON [Feb. 1, 



Family Daphniiba 

 Genus Simocephalus Schcedler. 



SlMOCEPHALUS CORNIGER, Sp. 11. (PL XV. fig. 41 & PI. XVI. 



fig. 42.) 



Length 2 - 34 mm.; height P76 mm. Body sub-ovate; head 

 region defined from thorax by a dorsal notch ; the shape of the 

 body resembles that of S. vetidus described by Lilljeborg (loc. 

 cit.) and figured on pi. xxiv. fig. 8 ; the ventral margin of the 

 carapace is provided with a row of minute spines reaching back- 

 wards from near the head along a considerable portion of its 

 length ; through three quarters of this length but slightly 

 internal to the row of spines, lies a line of closely-set stiff hairs : 

 posterior to these structures, the carapace is furnished with a 

 single row of short stout spines which reach almost as far as the 

 posterior limit of the ventral margin of the body ; they are 

 smallest at the posterior region of the carapace. Nearly the 

 whole surface of the body is covered with minute prickles. The 

 carapace is striated (only a portion is shown striated in fig. 41). 



The two large claws of the telson are serrated, and at the 

 base of each lies a group of small seta?. Of the other spines the 

 largest are curiously bent ; each carries a group of set* ; further, 

 groups of minute hairs, generally five or six to each group, 

 are produced on the inner part of the telson ; their limits are 

 best realized on reference to fig. 42. 



Locality. This species was found in Lake Chrissie, but occurs 

 more abundantly in a little reed-pan three miles east of Chrissie. 



Genus Daphnia 0. F. Midler. 



Daphnia pulex. (PI. XV. figs. 40a-c.) 



A few adult forms were found in Lake Chrissie, and a quantity 

 of young in a dam near Erasmus' Farm, Pretoria. As already 

 mentioned this Daphnia appears to be similar to the European 

 form. There is one point in which it differs from D. pulex, but 

 it is so insignificant, that it was not thought desirable to give 

 this species specific distinction from D. pulex. The ■ point is, that 

 caudal styles and dorsal processes just in front, which project 

 into the brood-chamber, are quite smooth. This South African 

 form was not found to differ from the European representative in 

 any other detail. 



Daphnia gibba, sp. n. (PI. XV. figs. 39 a, b.) 



Length with tail 6 mm. Body rotund, but dorsal part of head 

 and neck region enlarged to form a hump. Carapace striated. 

 Tail, which is fairly long, covered with small spines which run a 

 short way up the carapace and also ventrally extend along the 

 margins of the carapace as far as the head. 



