NORTH AMERICAN SALMONIDAE 



249 



\nadykov (1954) does not give the source of his 

 samples of SalvelinuH (table 16) but coinparisoii 

 of the variances and ranges of his sample counts 

 with those of Mottley suggests (table 17) that 

 each of his individual samples may not be from 

 one locality. The great variation in both ranges 

 and variances casts doubt on the utility of making 

 any but very broad generalizations fi-om these 

 available data, and also casts serious doubt on the 

 utility of using normal probability estimates for 

 describing distributions of discrete variables that 

 have such a small range. 



Saluelinus fontirudis, apparently, is signifi- 



cantly lower in vertebral count than either C. 

 namaycush or other species of Salvelinus. 



The extremely large variances (table 17) in 

 some of the samples of Oncorhynchus are appar- 

 ently caused by undercounting in the smaller fry. 

 Therefore, in table 18 the adjusted values are used 

 for four of the species of Oncorhynchus. 



The values for the vei'tebral counts are sum- 

 marized in figure 5, which shows that the count is 

 highest in Oncorhynchus and lowest in Salmo 

 solar, S. trutta, and Salvelinus fontirudis. All of 

 the other species occupy an intermediate position 

 with respect to this character. 



Table 16. — Count of vertebrae in Salvelinus and Cristlvomer 

 [x Indicates vertebrae present in frequency column, but no numbers given] 



' Vladykov (1954). 



' DeLacy and Morton (1943); Karlulc River, Alaska; count increased by 2 

 to include all vertegrae. 

 ' Wilder (1952); anadromous stock, Moser River, Nova Scotia; coimt 



increased by 3 to include all vertegrae. 



* Wilder (1952); resident stock, Moser River, Nova Scotia: coimt increased 

 by 3 to include aU vertegrae. 



Table 17. — Ranges and variances of vertebral-count distributions 

 [Presumably individual samples] 



' See bottom of table 15. 



