ARCHED-FRONTED SWIMMING-CRAB. 



97 



DECAPOD A. 



BRACHYURA. 



PORTUNIDJE. 



ARCHED-FRONTED SWIMMING-CRAB. 



Portunus arcuatus. Leach. 



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

 the penultimate tooth the smallest. 



Portunus arcuatus, 

 Rondeletii. 



Var. fronte emarginato. 

 Portunus emarginatus, 



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 1'Eur. Merid. V. p. 2. EDW. Hist. 

 Nat. Crust. I. p. 444. 



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



I HAVE followed Milne 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 



