M.J. ORLOVA-BIENKOWSKAJA 

Fig. 15 Age variation in shape. A, S. vetulus female, B, S. exspinosus female, C, S. vetulus male postabdomen. 
from 11 localities in Australia: New South Wales, Victoria, Queens- 
land, Northern Territory. The material is in AM and AC. 
DIAGNOSIS. Measurements. 9 Qad.: 1.0—2.4mm.,2 Qe.: 1.2-1.9. 
Female. Dorso-posterior valve prominence long, with very wide 
base and small diameter (Fig. 26). Its diameter less than its length 
(Fig. 2). Dorsal valve margin very heigh, protruding backward 
strongly. Depressions above and below dorso-posterior prominence 
wide and deep. Ventral head margin always with prominence, with- 
out depression under eye. Depression on ventral head margin near 
rostrum very shallow, sometimes absent. Ocellus elongate. 
Male. unknown. 
DISTRIBUTION. (Fig. 21) Australia. 
REMARKS. The original description of this species (Sars, 1896) is 
comprehensive and provided with good illustrations. Dumont(1983) 
supposes S. gibbosus and S. elizabethae to be subspecies of S. 
vetulus. Examination of S. gibbosus type material and specimens of 
S. elizabethae shows that these species differ from S. vetulus in the 
shape of the valves and head. In addition, they are sympatric and 
consequently cannot be subspecies of one species. 
S. elizabethae (King, 1853) 
Fig. 27 
Daphnia Elizabethae King, 1853a: 247; Simocephalus vetulus: 
Schédler, 1877: 18 partim, Negrea, 1983: 138 partim; S. vetulus 
elizabethae: Dumont, 1983: 98; S. dulvertonensis Smith, 1909: 81. 
