Bull. U. S. B. F. 1912. 



Plate LXVI. 



Fig. 26. — Brook trout, .showing massive thyroi<l tumor in the mouth cavity, springing from the fl<x)r of the mouth. 



Fir.. 27. — Two year old brook trout, showing massive tumor filling the entire gill space. 



Fig. 28. — Brook trout, showing tumor mass at the tip of the lower jaw. 



