2 Universily oj Michigan 



division of other elements of the fauna of western North America. 

 Additional material will probably permit the separation of an 

 Alaskan subspecies. 



But whatever systematic treatment we may decide to accord 

 these forms, it appears demonstrated that the fin-rays increase 

 gradually in number northward, being fewest in the warm bays of 

 southern California and most numerous along the colder coast of 

 Alaska. Other similar cases will be recorded bv the writer. 



\ 



The following two tables illustrate this northward increase in 

 the number of dorsal and anal fin-rays in Leptocotlus armalus. 

 The last ray in each fin is counted as branched; this ray having 

 obviously been listed as two by Nichols, his counts are all decreased 

 by one. 



