174 AUSTRALIAN MALACOSTRACA. 



Sub- Family Parastacidce. 

 Podobranchia? without or with a rudimentary lamina. First 

 abdominal somite devoid of appendages in either sex. Telson 

 never divided by a transverse hinge. 



Genus Astacopsts, Huxley. 



Epistome long and flattened. Basal joint of the antennae 

 fixed by the overlapping edge of the cephalostegite ; squame 

 short. Posterior thoracic sterna narrow. Coxopodites of the 

 hinder thoracic limbs large and approximated in the middle line. 

 Eostrum straight. Podobranchia? not alate. 



Section A. Telson aud caudal appendages membranaceous 

 with calcareous pieces at the edge. 



324. Astacopsis serratus. 



Cancer serratus, Shaw, Zool. of New Holland, pi. viii. 



Astacus armatus, E. von Martens, Ann. Mag. Nat. Hist. (3) 

 Vol. xvii., p. 359. 



Astacoides spinifer, Heller, Eeise der Novara, Crust., p. 102, 

 pi. ix. 



Potamobius serratus, "White, P. Z. S., 1850, p. 95, pi. xv. ; 

 McCoy, Ann. Mag. Nat. Hist., xx., 1867, p. 189. 



Astacoides serratus, E. von Martens, Monatsber, Akad. "Wiss. 

 Berlin, 1868, p. 615. 



Australian Crayfish, Huxley, " The Crayfish," fig. 76. 



Sides of the carapace on the hepatic and branchial regions 

 furnished with scattered conical spines, each enlarged at its base. 

 Eostrum about as long as the peduncles of the outer antenna?, 

 pointed and furnished on each side with four teeth ; its borders 

 continued backwards for a short distance on the carapace in the 

 form of a ridge. A spine placed behind the middle of the orbit, 

 continued backwards into a similar shorter ridge. Scales of the 

 outer antenna? pointed. Merus of chelipedes with a row of 

 sharp spines on its inner border, two or three spines on its upper 

 surface, and a row of small irregular teeth on its upper border ; 

 carpus with two or three prominent spines on its inner surface, 

 the first the longest and one or two on the outer surface. 

 Hand with both borders armed with a row of short spines bent 

 forwards, and forming a double row on the external edge and a 



