NOTES ON THE CRAYFISHES. 



AsTACOPSis AusTRALASiENSis (Milne Edwards). 



Astacus auslralasiensis M. Edw., Hist. Nat. Crustacfis, 1837, 2, p. 332, iil. 24, f. 1-.5. 



There are two cotypes of this species in the Museum of Natural History 

 in Paris. One of these, a female, has been kindly loaned to me by Prof. E. L. 

 Bouvier. The rostrum of this specimen is long-triangular, excavated, the 

 acumen provided with an upturned, blunt, apical denticle and a similar denticle 

 on each side ; behind the lateral denticles the margins of the rostrum are obscurely 

 crenate. The post-orbital ridges terminate anteriorly in a blunt tubercle; 

 they are channelled throughout their length and are followed by two obsolescent 

 tubercles at a little lower level on the gastric region; the hepatic area also is 

 tuberculated and a few less prominent tubercles are visible on the posterior 

 margin of the cervical groo\e on each side of the carapace. The areola is broad, 

 narrowing from before backward, punctate. Bi-anchial regions obsoletely squa- 

 mose. Abdomen rather smooth, with a submarginal row of small tubercles on 

 the pleura of the second somite; pleura rounded. Spine on dorsal face of inner 

 branch of posterior abdominal appendages submarginal. Antennal scale of 

 moderate width, flanked with a sharp denticle on the outer side at the base. 

 Anterior process of the epistome triangular, wdth convex sides, ending anteriorly 

 in an attenuated angle. Chelipeds nearly symmetrical, meros armed below 

 with spines biserially disposed, upper margin thereof also furnished with a few 

 (three or four) spinules; upper margin of carpus armed with two prominent 

 spines, the distal the larger; outer face furrowed longitudinally, slightly tubercu- 

 late along the upper edge of the furrow; inner face of the carpus somewhat 

 tuberculate and armed with one spine in the middle of the distal border. Propo- 

 dite distinctly carinate on the upper border, less distinctly so on its lower border; 

 the superior crest is cut into five teeth, the lower margin is denticulate; the outer 

 face of the propodite is thickly covered with depressed tubercles. Dactylus 

 furnished with one denticle near the proximal end of the upper border. Length, 

 63 mm.; length of carapace, 30.5 mm.; breadth of carapace, 13 mm.; length of 

 areola, 9 mm.; breadth of areola at anterior end, G mm., at posterior end, 4.5 

 mm.; length of chela, 20 mm.; breadth of chela, 10 mm.; length of dactylus, 

 11.5 mm. 



Bay of Sydney, Verreaux, No. 944, 1837. 



