THE SALMON TRIBE 



2869 



carnivorous fishes so largely feed. Fossil marine salmonoids, some of which belong 

 to existing genera, are known from the upper Cretaceous period, several of them 

 apparently connecting the family very closely with the herrings. As mentioned 

 before (p. 2862) the more typical members of the family have the parietal bones of 

 the skull separated from one another by the supraoccipital, but in Coregonus and 



SALMON AND SEA TROUT. 

 (One-sixth natural size.) 



Thymallus they unite in front of it. There is, however, a genus (Stenodus} 

 in which both conditions exist, so that there is no justification for making the 

 union of the parietals a reason for referring Coregonus to a family apart. In all 

 cases the supraoccipital extends forward to join the frontals (passing beneath the 

 parietals in the genera where those unite), and is thus quite different from the con- 

 dition obtaining in the carps and characinoids. 



