142 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



primary 

 afferent 

 blood vessel ^ 



gilf 



?** filaments 



primary 

 efferent 

 blood 'vessel ' - 



tertiary 

 efferent 

 vesse/-. 



tertiary 

 septum 



^cuticle 



secondary 

 efferent 

 blood 

 vesse/ 



-secondary 

 afferent 

 6/ood 

 vesse/ 



filaments 



^6/ood vesse/s 



Figure 78. — Blood circulation of gills. A. Dorsal, and B. ventral views of single gill lamina. C. Lateral view of 

 single gill filament showing circulation. D. Lateral view of single gill lamina. 



