COMMON RIVEK CRAYFISH. 



DEC A POD A. 



MACnOURA. 



237 



ASTACID.E. 



COMMON RIVER CRAYFISH. 



Astacus fluviatilis. Auct. 



Specific Charadcr. — Rostrum as long as the peduncle of the external antennae, 

 with a slight elevation along the middle, and a small tooth on each side about 

 one-third from the extremity. Carapace granulated. 



Cancer fltiviat'dis, 

 Astacus, 

 Cancer Axtacus, 

 A stacus Jluviutilis, 



Rondel, Poiss. II. p. 10. 

 Gesner, Aldrov. et al. auct. 

 Linn. Syst. Nat. II. p. 1051. 

 Fabr. Suppl. p. 406. — Latr. 



235. — Leach, Diet, des c 



Crust. II. p. 330. 



Hist. Nat. Crust. V. p. 

 Nat. — Edw. Hist, des 



This, the only European species of the genus Astacus, 

 may be readily known from others by the characters above 

 given ; although the general aspect of the whole of them is 

 so similar, that they might at a cursory glance be readily 

 confounded. 



