ARCHED-FRONTED SWIMMING-CRAB. 



97 



DECAPOD A. 



BBACHYURA. 



PORTUNIDJE. 



ARCHED-FRONTED SWIMMING-CRAB. 



Portunus arcuatus. Leach. 



Specific character. — Front entire, arched ; latero-anterior margin five-tootlied 

 the penultimate tooth the smallest. 



Portunus arcuatus, 

 „ Rondeletii. 



Var. fronte emarginato. 

 Portunus emarginalus. 



Leach, Malac. Brit. t. vii. f. 5, 6. W. Thompson, 

 Ann. and Mag. Nat. Hist. X. p. 283. 



Risso, Hist. Nat. des Crust, de Nice, t. i. f. 3. Id. 

 Hist. Nat. de I'Eur. Merid. V. p. 2. Edw. Hist. 

 Nat. Crust. I. p. 444. 



Leach, 1. c. vii. f. 3, 4. 



I HAVE followed ^Millie Edwards in adopting the sug- 

 gestion of Leach, that the Portunus emarginatus of the 

 latter is only a variety of his P. arcuatus. In retaining 



