22 



MAIAD^E. 



DECAPOD A. 

 BRACHYURA. 



MAIAD&. 



FOUR-HORNED SPIDER-CRAB. 

 Pisa tetmodon. Leach. 



Specific character. Lateral margin with four spines, (exclusive of those above 

 and behind the orbit.) Posterior portion of the carapace rounded, without spines ; 

 a small tubercle near the posterior margin. 



Cancer tetraodon> PENN, Brit. Zool. IV. t. viii. f. 2. p. 11. 



Maia Bosc, Hist. Crust. I. 254. LEACH, Edinb. Encycl. VII. 



p. 395. 



Blastus LEACH, 1. c. p. 431. 



Pisa LEACH, Trans. Linn. Soc. XI. p. 328. Id. Encycl. Brit. 



Supp. I. p. 415. Id. Malac. Brit. t. xx. f. 1-4. 



EDW. Hist. Crust. I. p. 305. COUCH, Cornish Fauna. 



p. 65. 



THE general form of the body of this species is trian- 

 gular, produced anteriorly, and with the posterior angles 

 much rounded. The rostrum is large, strong, and promi- 

 nent, about one-third as long as the remainder of the cara- 



