22 FRESHWATER AND LAND CRAYFISHES OF AUSTRALIA 
the third segment of second antennae, terminal spine short and sharp. Inter- 
antennal spine short and broad, sharply pointed. 
Carapace shorter than abdomen, as high as broad, twice as long as broad; 
cervical groove deeply impressed, areola fairly broad ; branchiostegites punc- 
tate, minutely tuberculate on some examples, a row of large tubercles behind 
cervical suture. 
Sternal keel very’ sharp; first three pairs of lateral processes very small, 
posterior pair small and slightly grooved ; processes between fourth pereopods 
short and stout. 
Telson with a spine on each lateral margin at junction of membranous 
portion ; inner rami of uropods each with a median spine and an outer lateral 
spine at junction of membranous portion ; outer rami each with several sharp 
spines along transverse suture. Lobes at base of uropods with upper lobe 
produced into a long sharp spine. 
Great chelae long and stout; propodus two and one-half times longer 
than broad, upper margin serrated, lower margin smooth; cutting edge of 
propodus and dactydus each with one or two small tubercles. Carpus with 
a small sharp spine on upper margin. Merus with one or two small blunt 
tubercles on upper margin. 
Habitat. — Western Australia: Swan River (ty'pe locality) ; Perth (A. 
Blain, 1936); Northam, Avon River (E. Nelson, 1936); Chidlow’s Wells; 
Cannington; Korijekup; Harvey, Harvey River; Vasse River; Mundaring 
Weir; Toodyay. 
Type in British Museum. 
Popularly known as the Gilgy. Described from a series 
of 60 specimens received from Mr. A. Blain and Mr. E. 
Nelson. 
Amongst the material from Perth is a fine example of a 
gynandromorph (PI. IV, fig. 20c), a description of which is 
included here. Of the many hundreds of specimens examined 
during the progress of this paper it is the only such example, 
and is apparently the first to be definitely recorded from 
Australia. 
Length, 110 mm. 
Rostrum short and broad, reaching almost to end of first segment of 
first antennae, apex sharply upturned ; carinae sharp, carried well back on to 
carapace, without spines ; lateral carinae sharp, median carinae blunt. 
Squame of the second antenna on the left side curved inwards instead 
of continuing straight to apex. 
The carapace is broader in proportion to size than in the normal specimens, 
and the sternal keel much more raised and sharp. The external sexual organs 
of the male appear on the coxae of the fourth pereopod on the right side, 
and of the female on the second pereopod on the left side. 
The great chela on the left side is large and stout, and that on the right 
small and slender. 
Clierax quadricarinatm (von Martens). 
(PI. IV, fig. 19.) 
Astacus quadricarinatus von Martens, Monats. Akad. Wiss. Berlin, 
1868, p. 617. 
