44 PRESHWATEB EKTOHOSTRACA OP JJ".S.W. i. CLADOCEEA, 



DuNHEVEDiA CRASSA King. (Plate vi., figs. 4-4a.). 



Fii-st described by King (1852, p. 261) ; redescribed by Saxs in 1888. 



Female. Carapace, seen laterally, almost semicircular, dorsal edge boldly 

 arched, ventral almost straight, posterior edge truncated. A denticle present on 

 the infero-posteal corner. Seen from above the carapace appears obovate, not 

 constricted in the middle, posterior part tapering. Head bent down, rostrum 

 acute, curved. Eye large, ocellus much smaller, of irregnilar shape, situated 

 closer to the eye than to the rostral tip. Post-abdomen_ with a row of small 

 denticles; end-claws small, curved, with a single denticle at the base of each. 



Male. Smaller than the female, with hairs instead of denticles on the post- 

 abdomen. 



Distribution. — This species has a wide distribution in New South Wales, 

 having been collected at Dunheved, Varroville, Moss Vale, Bathurst, Cumbalum, 

 Mudgee, the University pond. It is recorded from Queensland, South Australia, 

 Java, Siam, Hawaii, India, Ceylon and South Africa. 



DUNHEVEDIA PODAGRA King. 



Described by King in 1852. I have not been able to obtain this form, so 

 quote King's original description. It is apparently specifically distinct from the 

 preceding species. 



"Antennae with the tubercle near the base very prominent. When seen 

 from the back the outline at the middle is concave. This species is much smaller 

 than Bunhevedia erassa. When a number of them are placed together in a glass 

 of water, they congregate near the surface. The intestine is much convoluted, 

 having in reality two whole turns, although they are not in the same or parallel 

 planes. 



Localitii. — Parramatta. 



Genus Pleuroxus Baird, 1843. 



Lateral outline of the carapace may be long and comparatively low, or short 

 and highly arched; the posterior margins are short. Infero-posteal corner sharp, 

 usually toothed. Head not carinate, rostrum long and pointed, sometimes bent 

 forward. Lip-plate large. Antennules short, antennae with 8 swimming bristles. 

 Pive pairs of legs present. Fost-abdomen armed with marginal denticles only; 

 end-claws with two accessory teeth. 



About 27 species have been described from all parts of the World; three of 

 them are found in New South Wales. 



Key to sjjecie's of Pleuroxus. 



A. Infero-posteal corner unarmed ' . . inermis. 



AA. Infero-posteal corner armed. 



B. Form short and high reticulatus. 



BB. Form long and narrow australis. 



Pleuroxus ixerjiis Sars. 



Described in 1896 (Plate 5, fig. 8). 



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

 arched, ventral straight posteriorly, bulging anteriorly. Infero-posteal corner 

 rounded off, quite unarmed. Head bent forward, rostrum long and pointed. 

 Sculpturing of the carapace lacking, except in the anterior portion, where about 

 ten conspicuous curved striae are present. Ocellus very much smaller than the 



