242 



FISHES. 



Esox lucius, Lota vulgaris, Petromyzon marinus, P. fluviatilis, 

 and P. Iranchialis ; and all recent investigations have resulted 

 in giving additional evidence of the affinity, and not of the 

 diversity of the two regions. 



In Europe and temperate Asia, as well as in North 

 America, mountain ranges elevated beyond the line of per- 

 petual snow would seem to offer physical conditions favour- 

 able for the development of a distinct alpine fauna. But 

 this is not the case, because the difference of climate be- 

 tween the mountain districts and the lowlands is much 

 less in this zone than in the Equatorial. Consequently the 

 alpine freshwater fishes do not essentially differ from those of 

 the plains ; they are principally Sahnonoids ; and in Asia, 

 besides, mountain-barbels and Loaches. Salmo orientalis was 

 found by Griffith to abound in the tributaries of the Bamean 

 river at an altitude of about 11,000 feet. 



