FORT UNIOjST OF CRAZY MOUNTAIN FIELD, MONT. 



183 



or 0.65 (almost exactly two-thirds, as stated by Gidley), and in one 

 specimen of Cjerox (that mth which Gidley made comparisons) this 

 ratio is 10.1:15.4, or 0.66, so that the different size, preservation, and 

 to a slight degree proportions evidently misled his eye when he sup- 

 posed the ratio to be significantly smaller in C. montanensis. The 



Figure i7.—Ctaenodon montanensis (Gidley), U.S.N.M. no. 8362, skull and jaws, left side. Three-fourths 

 natural size. (After Gidley, 1919, fig. 5.) 



FiGUEK Z8.—Claenodon montanensis (Gidley), U.S.N.M. no. 8362, skull, palatal view. Three-fourths 

 natural size. (After Gidley, 1919, fig. 6.) 



ratio of total widths is 0.47, or about half, as stated by Gidley, in 

 C. montanensis type, and 0.46 in the specimen of C.ferox, which again 

 is a wholly insignificant difference. Computation of the exact figures 

 also shows Gidley's impression that the vertical depths of the anterior 

 faces of these bones are relatively less than in C.Jerox to be mistaken. 

 They are in fact slightly, but not significantly, greater than in this 

 specimen of C. ferox. 



119212—37 13 



