BY MARGUERITE HENRY. d9 



DD. Rostrum broad semicircular Graptoleberis. 



CC. Carapace valves thick, gaping bslow Dunhevedia. 



BB. End-claws with two basal spines. 



C. Infero-posteal corner rounded off, usually unarmed . . . . Chydorus. 



CC. Infero-posteal corner distinct, usually armed. 



T). Posterior margin entire Pleuroxiis. 



DD. „ excised Alimella (some species). 



Genus C a ii p t o c e r c u s Baird, 1843. 



Body latei'ally compressed, head and valves cariuate. Infero-posteal angle 

 often toothed. Eye distant from the anterior cephalic margin. Antennae with 

 seven swimming hairs. Carapace longitudinally striated. Fost-abdomen more 

 than half as long as the eaxapace, bearing marginal denticles only; end-claws 

 with one basal spine and bearing a series of secondary denticles ending in a 

 spine half way along the claw. Twelve species are known, one of which occurs 

 in New South Wales. 



CAJipa-ocERCUS AUSTRAiis Sars. (Plate vi., flg-s. 3-3a.). 



Described by Sars in 1896 from a single specimen taken at Centennial Park. 



Female. Carapace, seen lateraldy, of oval form, greatest height in front of 

 the middle; dorsal and ventral edges evenly arched, posterior edges rounded. 

 Head large, crested, ending in a blunt rostrum. Eye of moderate size, ocellus 

 smaller, slightly closer to the eye than to the rostral tip. Surface of the cara- 

 pace longitudinally striated. Infero-posteal corners unarmed. Post-abdomen 

 slender, long; about twenty mai'ginal denticles present; end-claws long and 

 straight, a basal spine present and another spine half way along the claw. Length 

 .7 mm. 



Distribution. — N.S.W. : Centennial Park, Kendall, Port Stephens. It is also 

 recoi'ded from Victoria, Sumatra,, India, South America. 



Genus AcROPERUS Baird, 1843. 



Body compressed, head and valves carinate. Infero-posteal angle rounded 

 or acute, usually with teeth. Antennae with eight swimming hairs. Carapace 

 obliciuely striated. Post-abdomen without marginal denticles; end-claws as in 

 Camptocercus. Large intestinal caecum. Nine species known, two among the 

 New South Wales fauna. 



Key to species of Aeroperus. 



A. Infero-poBteal corner unarmed simtatus. 



A A. Infero-posteal corner bearing two teeth avirostris. 



ACEOPERUS AViROSTPjs Henry. (Plate vi., figs. 2-2a.). 



Proe. Roy. Soc. N.S.W., lii., 1918 (1919), p. 469. 



Distribution. — ^N.S.W. : Port Stephens, Kendall, Cumbalum. 



ACROPERUS siNUATUS Henry. 



Pi-oc. Roy. Soc. N.S.W., lii., 1918 (1919), p. 471, PL xl., figs. 5, 6. 



Distribution. — N.S.W. : Kendall, Lome. 



