1888.] AUSTRALIAN CLADOCERA. 15 



well-nigh hyaline young darting about in the water in the very 

 same manner as the parent animal, at times, too, hiding them- 

 selves in the loose mud. They rapidly increased in size, and alter 

 some time had their matrix loaded with eggs; but not one of the 

 specimens attained anything like the size of the first one that 

 appeared, and the number of eggs, or embryos, was much re- 

 stricted, rarely more than 2 and 4 in each specimen. At the 

 end of the month the specimens seemed to undergo a sort of 

 degeneration, no ova being yet produced; and at the beginning 

 of the next month they successively disappeared, without having 

 developed any so-called winter-eggs, and before any male speci- 

 men had made its appearance. At an earlier period 1 had how- 

 ever secured some specimens with a view to dissection and pre- 

 serving in spirit. 



Occurrence. — The mud from which the above-described form 

 was raised — a rather light clayey bottom-deposit — was. ac- 

 cording to the label, taken from a „Water Hole" at Cattle Sta- 

 tion — salt at high tides — 20 miles from Rockhampton. Though 

 several other aquaries were prepared with parcels of the same 

 mud, in none of them did the present form develop. On the 

 other hand, in the same aquary, that yielded this interesting 

 animal, several other Entomostraca also made their appearance, 

 viz., a single female specimen of a beautiful Branchipodidian, 

 apparently belonging to the genus Strepfooyhahu Baird, more- 

 over 3 of the species of LijiKcula; described in this paper, and 

 finally a single specimen of the remarkable Cypridian, X<>f<>r ;fr r/s 

 cinrjaknsis Brady. 



Warn. JDaphnidai. 

 Gen. Simoeephalus, Schoedeler. 

 2. Simoeephalus australiensis (Dana). 



Daphnia australiensis Dana. United States Exploring Expe- 



