34 
AUSTRALIAN FRESHWATER AND LAND CRAYFISHES 
telson and uropods are membranous. The rostrum and lateral 
carinae differ in the two species. 
Separated from C. albidus Clark, by the broader, more 
rounded rostrum ; the more slender sternal keel ; the narrow 
areola ; and the shape of the sternal keel. 
Described from a large series of specimens received from 
Mr. Consett Davis. 
CJierax rotundus sp. nov. 
Plate X, Fig. 2. 
Length of average adult specimen 107 mm. 
Rostrum short and broad, reaching base of second segment of first antennae, 
apex rounded ; carinae blunt ; lateral carinae feeble, each ending in a rounded 
boss. 
Squame of each second antenna very broad anteriorly, terminal spine short 
and sharp. Interantennal spine short and broad ; apex obtuse. 
Carapace densely punctate; branchiostegites densely, minutely tuberculate; 
cervical groove deeply impressed ; branchio-cardiac grooves deeply impressed ; 
areola narrow. Anterior of carapace as broad as posterior, giving an appear- 
ance of great rotundity. 
Abdomen densely punctate. Telson longer than broad, with a spine at 
apical third of each lateral margin; posterior third of telson membranous. 
Uropods longer than telson; inner rami each divided by a longitudinal median 
Carina ending in a small sharp spine at membranous junction; a spine on each 
lateral margin at middle; posterior half of uropods membranous; outer rami 
each divided at apical third by a transverse suture, numerous small spines 
along suture; each ramus divided by a longitudinal median carina ending in 
a small sharp spine at the transverse suture ; posterior two-thirds of uropods 
membranous. Lobes at base of uropods without spines. 
Sternal keel slender and sharp; first two pairs of lateral processes very 
small, third pair larger, posterior pair larger, flattened; processes between 
fourth pereopods short and stout. 
Great chelae short and stout; propodus one and three-fourths times as 
long as broad, upper surface punctate, upper margin serrated, lower margin 
smooth, several small tubercles along cutting edge, apex sharp ; a large patch 
of short setae on lower surface of propodus. Dactylus stout, punctate, upper 
margin smooth, several small tubercles along the cutting edge, apex sharp. 
Carpus with a stout, blunt spine on upper margin, upper surface with a few 
punctures; upper margin of merus smooth. 
Habitat. — Queensland: M,uddy River, Severn (E. Sutton). 
This species comes nearest to C. punctatm Clark, but may 
be distinguished by the form of the carapace, great chelae, and 
the sternal keel. 
Genus GEOCHARAX Clark. 
Geocharax Clark, Mem. Nat. Mus. Viet., x, 1936, p. 31; Clark, Proc. Roy. 
Soc. Tasmania, 1938, p. 118. 
The genus Geocharax is found in various localities in 
Victoria, on the north coast of Tasmania, and on Kangaroo 
