148 POTAMOBIUS FLUVIATILIS. 



IIIRUDO SANGUISUGA.— Horse Leech. 



Spec. Char. Body elongated, above brownish-green, 

 beneath greenish, cinereous, witli black spots. 



Hirtido vulgaris ; Raii Ins. 3. Hirudo sanguistiga, Lin. Syst. Nat. p. 1070. 



The Horse Leech inhabits Europe in ponds, and has been vul- 

 garly esteemed poisonous ; it seems, however, only to make a 

 larger wound, and its bite is more apt to produce a degree of inflam- 

 mation which sometimes proves troublesome. 



Class VIII.— CRUSTACEA. 



Invertebral animals, with a crustaceous or more or 

 less solid covering, provided with articulated members, 

 distinct organs of circulation, and respiring by 

 branchiae. 



XXIV. 



POTAMOBIUS FLUVIATILIS. 



The Craw-fish, 



Order Decapoda, Latr. Family Astacida, Leach. 



Gen. Char. Abdomen with the sides of its segments 

 sharp ; middle tail lamella bipartite. 



Spec. Char. Rostrum laterally dentated, the base with 

 one tooth on each side. 



Match* , Arist. de Anim. iv. 2. Kapnivos irordfjuos ; Diosc. ii. 12. Astacus; 



Plinii, Hist. Cancer astacus: Syst. Nat. Gmelin, p. 2963. Astacus; 



Pennant, Brit. Zool. iv. p. 24, t. 16, f. 1. Astacus fluviatilis ; Fabr. Suppl. 



Ent. Syst. 406; Latr. Gen. Crust, et Insect, i, 51. Potamobius fluviatilis ; 



Leach, MSS. 

 VEcrivisse de Riviere, Fr •, Gambcro, It.; Cangrejo derio,S[>.; Der Flusskrebs, 



Gcr. 



