KNUT DAHL. 



long anal fin and tail, and a Tail-coefficient II 1,60 or a very 

 slender tail. 



In examining the course of these relations in the single 

 individuals of the ahove-mentioned tables, I have found quite the 

 opposite to be the case. As a rule only one of the three 

 characteristic relations, if any, is situated within those values 

 of the curves w^hich are common to both species. 



When a salmon possesses a very high scale-figure, one or 

 both tail-coefficients have been situated outside the values of 

 the curves, common to both species or vice versa. 



When a trout e. g. has possessed a tail-coefficient ranging 

 among the highest values of the species, the scale-figure has not 

 been among the values, common to both species. 



The most interesting examples I have been able to find 

 among my material on trout, are 3 specimens of which Nr. 1 

 was caught in the Orkla, Nr. 2 in the Battenfiord, Nr. 3 in the 

 ocean a few miles south of Christianssand (S.). They are 

 respectively 34,5, 36 and 45 cm. long, all very shiny and 

 slender. 



The course of the 3 relations was: 



Length. 



Scale-figure. 



Tail- 

 coefficient L 



Tail- 

 coefficient IL 



Nr. 1 

 « 3 



34',5 cm. 

 36 „ 



45 „ 



17 

 17 

 16 



0,99 

 0,99 

 1,00 



1,56 

 1,60 

 1,53 



Nrs. 1 and 2 are undoubtedly the most shiny, slender and 

 salmon-like trout I have ever come across among the fishes 

 examined by me. 



In the case of the salmon I may refer to some of the 

 most striking cases that have occurred to me. 



