182 



JEREMIAH S, FERGUSON 





Fig. 7. The position and relations of the thyroid gland in Raia. 



Fig. 8. Injected lymphatics in the tunica adventitia of the right commissural 

 artery at its junction with the median hypobranchial. The specimen is from 

 Carcharias, the fish having been injected with ink at a point just ventral to the 

 right hyoidean hemibranch. The injection followed the lymphatics and was 

 traced as far as the median hypobranchial artery in one direction and into the 

 thyroid gland in the other. 



