324 AtDials of the ftonfli African Museuw. 



tively short and blunt rostrum, carrying at the end the antennulae, 

 and provided on each side with a distinctly prominent arched crest 

 extending upwards near the dorsal margin; the latter slightly pro- 

 tuberant in the ocular region ; lower edge of head behind the rostrum 

 abruptly bulging to form a very conspicuous hump-like protuberance. 

 Surface of shell apparently quite smooth, without any obvious sculp- 

 ture ; free edges of valves clothed with a double row of strong, spini- 

 form setae. Eye well developed, with distinctly prominent crystalline 

 bodies. Ocellus very small and located near the base of the rostrum. 

 Antennulae nearly straight, sublinear in form, with a row of very small 

 spmules inside; apical papillae of moderate size. Antennae rather 

 strongly built, with the proximal setae of lower ramus very coarse and 

 dark-coloured. Epipodite in all the legs simple, sac-like. Tail-piece 

 with the extremity conically produced and carrying on the tip the very 

 small recurved caudal claws ; anal denticles minute, almost hair-like ; 

 upper part of posterior edge nearly straight and very finely serrate 

 throughout ; caudal setae with the distal joint very short, but clothed 

 with long diverging hairs. 



Male scarcely half as large as female, and having the carapace com- 

 paratively much smaller, with the dorsal margin straight and termi- 

 nating in an almost rectangular corner. Head large in proportion to 

 the carapace, with the protuberance of the lower edge only slightly 

 indicated. Antennulae very much produced, fully half as long as the 

 body, and provided anteriorly with two delicate sensory setae, the one 

 about in the middle, the other nearer the base. First pair of legs, as 

 usual, each armed at the end with a strong claw. Tail-piece not much 

 differing in shape from that in female, though having the extremity 

 somewhat blunter. 



Body in female rather pellucid, with a more or less distinct yellowish- 

 brown tinge, that of male nearly colourless. 

 Length of female reaching 1*2 mm. 



Remarks. This new species is at once recognised from any of the 

 other forms belonging to the present genus by the very conspicuous 

 hump-like protuberance formed by the lower edge of the head behind 

 the rostrum. It also differs in the simple sac-like shape of the epipo- 

 dites of the legs. 



Occurrence.--! have reared this handsome species in great numbers 

 both from the mud taken at Port Elizabeth, and from one of the 

 parcels of mud kindly sent to me in 1909 by Dr. Purcell and taken 

 from a small dried-up vley on the Cape Flats. It also occurred 

 rather abundantly in an alcoholic sample taken by that gentleman 

 from about the same locality, and kindly sent to me for examination. 



