Vomer 



Tongue 



Loterol Parr marks Dorsal 



line 





Adipose 

 fin 



Coudol 

 fin 





-■/ 



^sS----/ 



Moxiilory Pectoral Scales 1'^'^ Fleshy Anol 



fin Pelvic appendage fin 



fin 



Figure 1. — A hypothetical salmonid showing external characteristics. 



4. (17) Anal fin higher than long, with 8 to 



12 developed rays (Fig. 2A) 



5. (52) *Teeth on head and shaft of vomer. 



(Fig. 3A) 



LENG-rw^-^ 



Genus Salmo 



Genus Oncorhynchus 



Figure 2. — Anal fins: (A) Trout, genus Salmo; (B) Pacific salmon, genus Oncorhynchus. The two drawings 

 show differences in structure and fin ray count. (Note that the length of the anal fin is its overall basal length, 

 and its height is that distance from the origin of the fin to the tip of the anterior lobe. In counting fin rays, in- 

 clude only those which originate from the base and terminate at the outer margin of the fin or are half as long 

 as [or greater than] the longest ray.) 



