1888.] AUSTEALIAN CLADOCEBA. 63 



Tail of male of conical form, tapering to an obtuse point, with- 

 out any distinct supraanal angle, and wanting dorsal denticles; 

 caudal claws inserted a little behind the apex, rather small, and 

 without any trace of a secondary denticle. Colour light yellow- 

 ish, dorsal part of carapace in females with winter-eggs some- 

 what darker. Length of adult female 0.38 mm, of male 0.28 mm. 



Bemarks.. — This species is very nearly related to the Eu- 

 ropean species, A. parvula Kurz ; but would seem to -differ in 

 having a somewhat different sculpture of the shell, as also by cer- 

 tain minor differences in the form and amature of the tail.' In 

 general habitus too the animal pretty much resembles the two 

 preceding species, though having a relatively shorter and stouter 

 carapace. 



Description. — The length of the adult female does not at- 

 tain fully 4 mm, and this species is thus somewhat inferior in 

 size to the two preceding ones. 



The carapace of the adult female, as seen laterally (PI. 6, 

 fig. 7), is rather short aud stout, nearly as high as it is long, 

 and of a rounded quadrangular form, with the posterior extre- 

 mity truncated. The dorsal edge is rather boldly arched in the 

 middle and terminates posteriorly with a distinct, though obtuse, 

 angle. The infero-posteal corners, on the other hand, are evenly 

 rounded off. The inferior edges of the valves are throughout 

 the greater part of the length straight, but anteriorly they as- 

 cend obliquely to the infero-anteal corners. The head is some- 

 what depressed, but exhibits on the whole a form very similar 

 to that in the two preceding species, terminating in a rather 

 prominent acute rostrum, projecting a little beyond the inferior 

 edges of the valves. 



The surface of the shell, when the animal is wholly sub- 

 merged in the water, appears quite smooth; but as soon as it 

 rises to the surface, the side out of the water displays a very 

 elegant sculpture, consisting of a dense and rather regular reti- 

 culation, the meshes as a rule arranged in longitudinal rows. 

 This beautiful sculpture is more especially very conspicuous in speci- 

 mens provided with winter-eggs, but may also be traced pretty 



