666 C. JUDSON HERRICK AND JEANNETTE B. OBENCHAIN 



Fig. 1 Dorsal view of a wax model of the cerebrum and rostral end of the rhomb- 

 encephalon of Ichthyomyzon concolor (Kirtland). X 50. The model was made 

 at a magnification of 75 diameters and the illustrations were drawn by Mr. A. B. 

 Streedain the same size as the model. Figures 1 to 4 were reduced to two-thirds 

 of the dimensions of the drawings and figures 5 to 12 were reduced to one-half. 



