154 MEDITERRANEAN PROVINCE. 



the same name, and includes a large portion of the 

 Lusitanian zone. 



Owing to the works of Leach, Desmarest, and 

 others, we have long had a knowledge of the Crus- 

 tacea of our own shores as well as of those of Brit- 

 tany and the Mediterranean, to the exclusion of 

 such as occurred on the south-western coasts of 

 France, and the Atlantic border of Spain and Por- 

 tugal. As M. Milne Edwards carries his Celtic 

 region as low as Gibraltar, the assemblage from that 

 region seemed to present an amount of distinctness 

 from the Mediterranean which does not really exist. 



The forms which may be considered Celtic in the 

 restricted sense of the present work, are the Swim- 

 ming Crab (Polybius Ilensloivii) of the west of 

 France and England, Hyas coarctatus, Athanas 

 nitescens, and Pandalus annulicomis. Other species, 

 such as the Great Crab (Cancer pagurus), the com- 

 mon " Shore-Crab," Carcinm mcenas, and Portunus 

 puber, have their numerical maximum within our 

 region ; its negative character, as a Zoological pro- 

 vince, consisting in the absence or scarcity of Cato- 

 metopes, Anomoura, and Squilla. In general terms, 

 the Celtic Decapod Crustaceans of our coasts are to 

 be met with in the Mediterranean ; some of our 

 common forms become scarce there, and vice versd, 

 indicating both the changes which take place across 

 the Lusitanian zone, and the source or direction 

 in which the Mediterranean has derived a large pro- 

 portion of its Crustacea. 



