be referred to another page where again there will be 

 offered a choice of characters under the headings I and 

 II. Or you may be referred on the same page to a choice 

 of characters under subheadings la and lb, and possibly 

 to still further subheadings 1 and 2, a and b. The differ- 

 entiating characters described under the various headings 

 are illustrated in silhouettes of fishes, usually on the page 

 opposite. 



After the fish has been identified the key refers the 

 reader to a section in the rear part of the book (General 

 Information), where the fish is illustrated and a descrip- 

 tion given of its color, distribution, size, habits, and eco- 

 nomic importance. 



Alfred Perlmutter 



