2D8 DISTRIBUTION AND /ETIOLOGY OF THE CRAYFISHES. 



specimens of English and Irish crayfishes which have 

 passed through my hands, have all presented the charac- 

 ter of Astacus torrentium, with which also the description 

 given in works of recognised authority coincides as far as 

 it goes.* The same form is found in many parts of 

 France, as far south as the Pyrenees, and it is met with 

 as far east as Alsace and Switzerland. I have recently f 

 been enabled, by the kindess of Dr. Bolivar, of Madrid, 

 who sent me a number of crayfishes from the neighbour- 

 hood of that city, to satisfy myself that the Spanish 

 peninsula contains crayfishes altogether similar to those 

 of Britain, except that the subrostral spine is less de- 

 veloped. Further, I have no doubt that Dr. Heller | is 

 right in his identification of the English crayfish with 

 a form which he describes under the name of A. 

 saxatilis. He says that it is especiall}^ abundant in 

 Soutliern Europe, and that it occurs in Greece, in 

 Dalmatia, in the islands of Cherso and Vegiia, at Trieste, 

 in the Lago di Garda, and at Genoa. Further, Astacus 

 torrentium appears to be widely distributed in North 

 Germany. The eastern limit of this crayfish is uncertain ; 

 but, according to Kessler,§ it does not occur within the 

 limits of the Russian empire. 



* See Bell. " British Stalk-eyed Crustacea," p. 237. 



t Since the statement respecting the occurrence of crayfishes in Spain 

 on p. 44 was printed. 



t " Die Crustaceen des Sildlichen Europas," 1863. 



§ " Die Russischen Flusskrebse." Bulletin de la Societd Imporiale 

 des Naturalistes de Moscow, 1874. 





