5. Adipose fin present 



/4^ 



Adipose fin absent 9 



6. Barbels on head; scales absent; single stout spine in dorsal and 

 pectoral fins 



Brown Bullhead 

 Ictaliiridae 



p. 67 



Barbels absent; scales present; pectoral fins without spines . . 7 



7. Mouth small; upper jaw not extending back to below center of 

 eye; teeth on jaws and tongue weak 



Whitefishes 

 Coregonidae 



p. 52 



Mouth large; upper jaw extending back at least to below center 

 of the eye; strong conical teeth on jaws and tongue 8 



12 



