FRESHWATER AND LAND CRAYFISHES OF AUSTRALIA 
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median carina feeble, ending in a sharp spine near posterior margin; outer 
rami of uropods each with numerous spines along transverse suture, some 
examples having two or three small spines on outer lateral margin. Lobes at 
base of uropods without spines. 
Sternal keel rounded below first and second pereopods, sharp below great 
chelae ; first pair of lateral processes very small and sharp, second pair larger, 
and third pair four times as large as first, rounded ; posterior pair large, blunt, 
and deeply grooved ; processes between fourth pereopods long and stout. 
Great chelae stout, propodus two and one-half times as long as broad, 
upper margin with four sharp spines, lower margin with a double row of 
sharp spines, cutting edge with two large and several small tubercles ; dacty- 
lus with several small tubercles on cutting edge, upper margin usually smooth, 
sometimes with one or two small sharp spines. Carpus with two long sharp 
spines on upper margin, upper surface deeply grooved; merus with three large 
and five small sharp spines on upper margin. 
Colour. — The colour, chiefly in shades of blue and bluish-green, is subject 
to considerable variation at all stages of growth. McCulloch (1917) records 
bright pink examples from the Blue Mountains, New South Wales. In 
specimens received alive from Dr. W. J. Harris, of Echtica, Victoria, the cara- 
pace, abdomen and pereopods varied from light blue to very dark blue, but 
some were a light greenish-blue ; the dorsum of the carapace, spines on 
carapace, abdomen and pereopods, and the whole of the great chelae, white. 
Great variation is shown in the number and position of the spines in 
individuals of all sizes, particularly those on the rostrum and telson. In the 
series from Echuca no two examples are identical; some have numerous 
small spines on the upper surface of the telson, others only two or three 
spines, others again spines on the lateral margins only. In some specimens 
the rostrum has five spines on each side ; one has three spines on one side 
and two on the other ; another has one spine at each side of the apex and two 
very small tubercles behind the spines. The spines on the branchiostegites 
and abdomen also vary in number and size. 
Habitat. — Murray River and its tributaries in Victoria, Nezv South Wales 
and South Australia; Brisbane Waters (White, 1850). 
Described from a series of 60 specimens ranging in length 
from 50 mm. to 300 mm., from various localities in Victoria, 
New South Wales and South Australia. It is popularly 
known as the Murray Lobster, or Murray Crayfish. 
Local Varieties. — A series of seven specimens from the Jamieson River 
(A. Hordern, 1935) and a series of nine from the Goulburn and Howqua 
Rivers (E. Clark, 1935), although fairly close to serratus in general charac- 
ters, differ in having the spines on the carapace very small and less numerous ; 
and’ the second antennae barely reach the base of the telson. The largest 
examples (212 mm.) were cress green on the carapace, abdomen and pereo- 
pods, with the great chelae and all the spines white; a few examples were 
entirely green. Many of the smallest (90 mm.) were entirely dark reddish- 
brown, with the spines more reddish. 
Specimens from Buffalo River, Victoria (E. Clark, 1935), agree in general 
characters with serratus but the great chelae are very short and stout as in 
yarraensis, and the spines on the branchiostegites are smaller and less 
numerous than in serratus. Colour as in serratus. 
