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RECORDS OF W.A. MUSEUM. 
CHERAPS QUINQUECARINATUS, Gray. 
PLATE XXXIII. 
Astacus quinque-carinatus, Gray, in Eyre, Journ. Exped. Centr. Austr., I, 1845, 
p. 410, pi. Ill, fig. 3. 
Astacus (Cheraps) quinquecarinatus, Von Martens, Monatsbr. Akad. Wiss Berlin 
1868 (1869), p. 616. 
Astacopsis quinque-carinatus, Haswell, Cat. Austr. Crust. 1882, p. 176. 
Chaeraps quinque-carinatus, Smith, Proc. Zool. Soc., 1912, p. 165, pi XXIII and 
XXVII, fig. 25-29. 
I have examined thirty-eight specimens of all sizes between 45 
and 131 mm. long, from the tip of the rostrum to the end of the 
telson, and find but little variation in the essential characters of this 
species. There are some differences in the form of the chelae, 
which consist chiefly of an alteration in the shape of the fingers, 
they being narrow and somewhat pointed in some, and much 
broader and more obtuse in others. A tomentose patch on the 
upper surface of the hand, near the inner margin, is usually present, 
but may be absent. 
Carapace finely pitted above ; large specimens with some very 
minute tubercles on the lower anterior parts of the sides. A row 
of enlarged tubercles behind the cervical groove. Back with five 
keels, of which two are backward extensions of the lateral margins 
of the rostrum. The median keel arises between these last, and 
may run backward to the cervical groove or terminate well before 
that point; the outer keels form two sharper or blunter points 
anteriorly. Rostrum either horizontal or rather obliquely deflexed 
not reaching the ends of the antennal scales ; its sides are elevated, 
leaving the upper surface more or less concave. It ends in a spine, 
and there are usually two, rarely one or three denticulations on 
each side near the tip. Its length and breadth is subject to a little 
variation. Abdomen pitted but otherwise smooth. 
Chelipeds rather massive. The hand is comparatively elongate, 
its breadth being always distinctly less than half its length. It is 
smooth and rounded above with small scattered pits, which are a 
little larger and more crowded on the outer surface ; the two largest 
specimens have a narrow, irregular groove along the middle of the 
upper surface. The inner margin is raised with seven to nine 
serrations; usually there is a tomentose patch just within this 
margin. Fingers either meeting along their entire length, or with a 
larger or smaller gape between them. They are armed with one or 
