48 FRESHWATER ENTOMOSTRACA OP N.S.W. 1. CLADOCERA, 



Alonella karua (King). 



First described by King as Alona karua (1852, p. 260). Described by Sars 

 m 1888 (Plate 5, figs. 8-9). 



Female. Carapace, seen laterally, somewhat quailraugular, broader anteriorly, 

 posterior edges abruptly truncated. Head depressed, terminating in a sharp 

 rostrum. Ocellus smaller than the eye and situated closer to it than to the tip 

 of the rostrum. Carapace marked with distinct striations. Infero-posteal corner 

 armed with 1-4 small teeth. Antennules slender, conical, not reaching the tip of 

 the rostrum. Post-abdomen dilated distally, apex broadly truncate, anal denticles 

 very small, about 8 lateral fascicles present; end-claws of moderate length, with 

 one minute basal spine. Length .4 mm. 



Distribution. — N.S.W. : Stroud, Port Stephens. North and South America, 

 South Africa, Sumatra, Java, Singapore, Siam, Cochin Cliina, Ceylon. 



Alonella diaphana (King). (Plate vii., figs. l-lo.). 



First described by King (1852, p. 260) as Alona diapltana. 



Female. Carapace, seen laterally, rounded oval, tapering posteriorly, angles 

 all rounded off. Head rather depressed, rostrum obtuse. Carapace striated, 

 striae rather close together, curved. Infero-posteal corner unarmed. Eye of 

 moderate size, ocellus smaller than the eye and situated midway between it and 

 the tip of the rostrum. Post-abdomen large, oblong in form, tapering slightly 

 distally, edge armed with small hair-like denticles, supra-anal angle slight; end- 

 claws each with one small basal spine. Length .49 mm. 



Distribution. — N.S.W. : Sydney, Moss Vale. Queensland, South America. 



Alonella escisa (Fischer). 



First described by Fischer as Lynceus excisus (1854, p. 428). 



Female. Carapace, seen laterally, roughly oval in outline, dorsal margin 

 evenly arched; ventral straight for the greater pai't of its length, ascending an- 

 teriorly; posterior narrowly truncated, with the upper and lower corners angulai'. 

 Head slightly bent down, rostrum of moderate size, sometimes long. Surface of 

 the carapace marked by a conspicuous network crossed with longitudinal striae, 

 anterior part marked with curved transverse striae. Infero-posteal corner some- 

 times produced into a point with the posterior margin above it excised, some- 

 times crenulated. Ocellus much smaller than the eye and situated nearer to it 

 than to the tip of the rostrum. Post-abdomen long, of almost uniform breadth 

 throughout; supra-anal angle prominent, marginal denticles small. End-claws 

 small, each with two unequal denticles at the base. Length up to .5 mm. 



Male. Much smaller than the female, the largest found measuring only .25 

 mm. 



Distribution. — Typical specimens were found at Lett River and Kendall in 

 N.S.W. It has not hitherto been recorded in this State. This species is known 

 from Europe, Siberia, Greenland, Iceland, North and South America and South 

 Africa. 



AiX)nella clathratula Sars. (Plate vi., figs. 6-6o.). 



Described by Sars in 1896. 



Female. Carapace, seen laterally, oblong oval, with the greatest height in 

 front of the middle ; dorsal margin evenly arched, posterior edges truncated. Head 

 depressed, terminating in an acute rostrum. Infero-posteal angle distinct, not 

 excised or crenulated as in the preceding species. Surface of the carapace reticu- 

 lated in the posterior portion and marked by curved striae anteriorly. Post- 



