AUSTRALIAN CLADOCEBA. 



53 



subsequently examined the aquary very closely, I did not succeed 

 in detecting any more specimens, and in the course of a few 

 days all life seemed to have become extinct in the aquary. 

 Any observations on the habits of this species I have thus been 

 unable to institute. 



Occurrence. — The aquary from which I got this species 

 was the same that yielded the two preceding Lynceidae; the 

 mud had been collected from a Water Hole at Cattle Station. 

 Mr. King also met with the species in a single locality, the 

 River Karua, near Stroud. 



Gen. Alona, Baird. 

 9. Alona Archeri, n. sp. 



(PI. 6, figs. 1-4). 



Specific Characters. — Carapace of adult female, as seen 

 laterally, oblongo - quadrangular, posterior extremity obtusely 

 rounded, with the upper and lower angles obsolete; inferior ed- 

 ges of valves nearly straight. Head semierect, hooded, terminat- 

 ing in an acute rostrum, projecting beyond the inferior edges of 

 the valves. Carapace of male more regularly quadrangular, in- 

 ferior edges subangular in front of the middle. Surface of shell 

 sculptured with small depressed pits arranged in longitudinal 

 rows, more distinct in females with winter-eggs. Ocellus much 

 smaller than eye, punctiform. Antennulse in female rather short 

 dilated in the middle, almost fusiform; in male much larger and 

 projecting considerably beyond the tip of the rostrum. Tail of 

 female rather elongate and narrow, obliquely truncate at the 

 tip, supraanal angle strongly projecting; outer part nearly pa- 

 rallel-sided and armed dorsally with a double row of denticles, 

 the outer ones much larger than the rest and spinulose at 

 the upper edge; a lateral row of 6 extremely delicate spines 

 present; caudal claws much elongated, with a distinct secondary 

 denticle at the base. Tail of male somewhat shorter and less 



