ON SOME AUSTRALIAN CLADOCERA. 475 
spines on the infra-anal margin with spinules on the pos- 
terior border of each. The end-claws are strong witha 
very well developed denticle at the base of each. A row 
of about twelve marginal combs is present. 
This species somewhat resembles Alona whiteleggii Sars, 
but differs in the greater width of the posterior edges, the 
straight dorsal margin and the more depressed head; the 
tail-piece is like A. whiteleggii in shape but has fewer spines. 
and further these possess spinules on their posterior edges. 
Specific Characters.—The carapace seen laterally, is 
quadrangular, very wide posteriorly; dorsal and ventral 
margins Straight. Posterior edges arcuate. Head depressed 
with a long acute rostrum. COarapace longitudinally stri- 
ated. Ocellus almostas largeastheeye. Tail-piece large,,. 
twelve pairs of spines on the infra-anal margin, provided 
with spinules; twelve marginal combs present, end-claws. 
and secondary denticles strong. Length 0°88 mm. 
Locality.— Kendall, collected in October. Type specimen 
in the Australian Museum, No. P 4331. 
ALONA LONGIROSTRIS Sp. 0. 
(Plate XLI, figs. 11, 12.) 
The length of the specimen examined is 0°74 mm. Seen 
laterally, the shell exhibits an oblique oval form, obliquely 
truncated behind; the greatest height is 0°41 mm. and 
occurs just behind the middle; the dorsal margin is arched, 
the ventral edges of the valves are straight for the greater 
part of their length, curving upwards posteriorly. 
The head is depressd, with an elongated pointed rostrum 
reaching below the ventral edges of the valves; the dorsal 
margin of the head forms an even curve with that of the 
carapace. 
The surface of the carapace is not striated but marked 
by a number of pits; the ventral edges of the valves bear 
