INSTRUCTION. 
The location of the fins of the fish mark the subdivi- 
sions of the families. The above diagram being supposed 
to represent a fish, and a Trout at that, g is the first back 
or dorsal fin, f the second — in the case of this species, 
mere rayless, fatty matter ; e is the tail fin or caudal — ■ 
the writer, as a married man, naturally avoiding the 
