American Fisheries Society 



F.d Td 



EXPLANATION OF FIGURES. 



Fig. 1. Diagram of a soft ray. 



Fig. 2. Diagram of a fin-spine. S., spine; W., web of fin. 



Fig. 3. Diagram of a simple ray. It possesses transverse segments 

 but no branches. 



Fig. 4. Diagram of a wax model of the spine of the common bull- 

 head, Ameiurus webulosus. Yd., first division of ray; Sd., 

 Td., Fd., second to fourth divisions respectively. Sr., 

 first soft ray of fin. 



