SjL freshwater entomostraca of n.s.w. i. cladoceea, 



Distribution. — N.S.AY.: Denham Court, "water holes off Bourke St.,'' Hol- 

 brook, Casino; also occurs in Victoria. It has not been recorded outside Aus- 

 tralia. 



SiMOCEPHALUs GIBBOSU.S Sars. (Plate v., figs. 3-3a.). 



First described by Sars in 1896 from specimens collected at Centennial Park. 



Female. Carapace, seen laterally, like a rounded triangle; dorsal margin 

 fairly straight, abruptly curved posteriorly, forming an asymmetrical expansion. 

 Posterior prominence distinct, obtuse. Head of moderate size, dorsal margin 

 evenly curved, ventral slightly convex. Eye of moderate size, ocellus prolonged 

 into a stripe. Cai-apace obliquely striated, both the expansion and the posterior 

 prominence denticulate. Fbst-abdomen not very broad, anned with twelve anal 

 denticles which increase in size distally. Length 2 mm. 



Distribution. — This species has only been found at Centennial Park and 

 Botany in N.S.W. ; Searle records its presence in Victoria. 



SiMOCEPHALUS sp. 



A single specimen of Simocephalus was present in a collection of Entomos- 

 traca taken at Byron Bay. Unfortunately this specimen is imperfect and there- 

 fore cannot be exactly identified; it is, however, obviously distinct from the four 

 preceding species, and bears a decided resemblance to the South American form 

 Simocephalus iheringi Richard (1897, p. 279). The chief feature of resemblance 

 is the acutely-pointed posterior prominence. 



Genus C E B I O D A p H X I A Dana, 1853. 



Valves of the carapace ending in a posterior angle or a short spine. Head 

 small and depressed, separated from the thorax by a deep cervical groove. Cara- 

 pace marked by a polygonal pattern. Antennules in the female not freely mov- 

 able. Ocellus always present. Ephippium triangular, containing one egg. 

 About thirty-eight s,pecies have been described from different parts of the 

 world ; three of these are found in New South Wales. 



Key to species of Ceriodaphnia. 



A. Head bearing one or two pointed projections cornuta. 



AA. Head without projection'i^ 



B. Posterior spine long spinata. 



BB. Posterior spine short honorata. 



Ceriodaphnia cornuta Sars. (Plate iv., fig. 4). 



Described by Sars (1885) from a single specimen reared from dried mud 

 which had been collected from the Gracemere Lagoou, near Roekhampton. 



Female. Carapace, seen laterally, oval in outline, upper and lower margins 

 of the valves slightly arched, posterior part produced as a short spiny process. 

 Head depressed, with the frontal part jutting out into two acute prominences, 

 the upper as a prolongation of the front, the lower taking the place of a rostrum. 

 Sculpture of the whole carapace a conspicuous network; free edges of the valves 

 devoid of hairs or spines. Eye of moderate size, ocellus very small, punetiform. 

 Antennules small, with a seta situated in the middle of the posterior margin. 

 Post-abdomen with two dorsal processes, armed with 6-8 anal denticles; end- 

 claws smooth. Length .0 mm. 



Distribution. — This species has not hitherto !)een recorded from N.S.W. It 



