22 



MAIAD^. 



DECAPOD A. 



BRACHYURA. 



MAIADJE. 



FOUR-HORNED SPIDER-CRAB. 

 Pisa tetraodon. 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, 

 Maia ,, 



Blastus „ 

 Pisa „ 



Penn, Brit. Zool. IV. t. viii. f. 2. p. 11. 



Bosc, Hist. Cnist. I. 254. Leach, Edinb. Encjcl. VI 1. 



p. 395, 

 Leach, 1. c. p. 431. 

 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 Avith the posterior angles 

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

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



