34 FRESHWATER ENTOJIOSTRACA OF N.S.W. i. CLADOCERA, 



Genus MoiN OD APH N I A Herrick, 1887. (Syn. Paramoina Sars.). 



Body compressed, valves elliptical, crested doi-sally; cervical sinus distinct, 

 dorsal and ventral margins forming a sharp angle posteriorly. Carapace marked 

 by oblique striae. Antennules attached on the ventral surface of the head, with 

 a sense hair situated about the middle of each. Ocellus present. One large 

 abdominal process. Post-abdomen slender, resembling the genus Moina. Only 

 two certain species are known, one of which is represented in N.S.W. 



MoiNODAPHNiA MACLEAYii (King). (Plate iv., fig. 6.). 



Syn. Moinodaphnia macquerysi Richard; Moina submucronata Brady. 



First described by King (1852, p. 251) as Moina macleayii; fully described 

 by Sars in 1901. 



Female. Carapace, seen laterally, rounded oval, dorsal margin strongly 

 curved posteriorly, ventral evenly curved, the junction forming a sharp angle. 

 Sculpture of the carapace consisting of very fine oblique striae, free edges armed 

 with tiny denticles. Dorsal margin of the head arched, ventral almost straight, 

 with a small prominence as a rudiment of the rostrum. Eye of moderate size, 

 ocellus small, situated close behind. Post-abdomen slender, bearing ten laterally 

 situated anal denticles; end-claws of moderate size. Length 1 mm. 



Distribution. — This is a rare species in N.S.W. ; it has only been obtained 

 from Elizabeth Bay and Byron Bay. It occurs in New Guinea, Sumatra, Siam, 

 Ceylon, Congo, North and South America. 



Genus Moina Baird, 1856. 



Body thick and heavy. Carapace without a spine, not completely covering 

 the body, cervical sinus present. Rostrum absent. Antennules long and mobile, 

 modified in the male to form clasping organs. Carapace valves obscurely re- 

 ticulated. Abdominal process represented by a horseshoe-shaped fold. Post; 

 abdomen bearing ciliated spines and a bident. Ephippium oval, containing one 

 or two eggs. Over twenty different species have been described; some of these 

 resemble one another closely and are often difiieult to determine unless males and 

 ephippial females are present. Three species occur in N.S.W. 



Key to species of Moina. 



A. Head with a sinus above the eye. 



B. Ephippium with two eggs australiensis. 



BE. Ephippium with one egg propinqua. 



AA. Head without a sinus above the eye tenuicornis. 



Moina australiensis Sars. 



Described by Sars in 1896 and fully figured (Plate 3, figs. 1-2). 



Female. Carapace rounded, varying in shape according to the condition of 

 the matrix. Head of moderate size, slightly depressed, with a distinct sinus 

 above the eye, ventral edge slightly convex at the insertion of the antennules. 

 Eye of moderate size. Antennules short. Post-abdomen tapering distally, 10-12 

 anal spines which are ciliated on both edges, last spine two-pronged; end-claws 

 smooth. Two eggs in the ephippium. Length up to 1.4 mm. 



Male. Head comparatively larger and less strongly arched above, ventral 

 edge straight, antennules armed at the tip with claws. First pair of legs pro- 

 vided with a claw as well as a curved spine and a long seta. Length up to .85 

 mm. 



