BULL. U. S. B. F. 1912. 



PLATE LXVI. 



FIG. 26. Brook trout, showing massive thyroid tumor in the mouth cavity, springing froiit the floor of the mouth. 



FIG. 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. 



