ASTACUS NOBILIS. 299 



Astacus torrentium appears to be particularly addicted 

 to rapid highland streams and the turbid pools which 

 they feed. 



Astacus nobilis is indigenous to France, Germany, and 

 the Italian peninsula. It is said to be found at Nice 

 and at Barcelona, though I cannot hear of it elsewhere 

 in Spain. Its south-eastern limit appears to be the Lake 

 of Zirknitz, in Carniola, not for from the famous caves of 

 Adelsberg. It is not known in Dalmatia, in Turkey, nor 

 in Greece. In the Kussian empire, according to Kessler, 

 this crayfish chiefly inhabits the watershed of the Baltic. 

 The northern limit of its distribution lies between Chris- 

 tianstad, in the Gulf of Bothnia (52° 16' N), and Serdobol, 

 at the northern end of Lake Ladoga. " Eastward of 

 Lake Ladoga it is found in the Uslanka, a tributary of 

 the Swir. It appears to be the only crayfish which exists 

 in the waters which flow from the south into the Gulf of 

 Finland and into the Baltic; except in those streams and 

 lakes which have been artificially connected with the Volga, 

 and in which it is partially replaced by A. leptodactylus:'' 

 It still inhabits the Lakes of Beresai and Bologoe, as 

 well as the aflluents of the Msta and the Wolchow ; and 

 it is met with in aflluents of the Dnieper, as far as 

 Mohilew. Astacus nohilis is also found in Denmark and 

 Southern Sweden ; but, in the latter country, its intro- 

 duction appears to have been artificial. This crayfish 

 is said occasionally to be met with on the Livonian coast 

 in the waters of the Baltic, which, however, it must 



