10 DESCRIPTION OF A SKULL OF MEGALONTX LBIDYI, N". SP. 



EXPLAIS^ATIO^ OF THE PLATES. 



Plate I. 



Lateral view — two-thirds natural size. 



Plate 11. 



Superior view — two-thirds natural size. 



Plate III. 



Inferior view — two-thirds natural size. 



Plate IV. 



Fig. 1. Anterior view — two-thirds natural size. 

 Fig. 2. Posterior view — two-thirds natural size. 



Plate V. 



Figs. 1, 3 and 5. Sections of skull of M. leidi/i 



(see page 7). 

 Figs. 2, 4 and 6. Sections of skull of M. jeffersoni 



Fig. 7. Dentition — natural size, and arranged on the plate in natural position. 



Figs. 8 and 9. Views of exterior side and triturating surface of left canine molar ; natural size. 



P. S. — Prof. E. D. Cope, in letters to Prof. Udden, determined the teeth of Equus major, found in the same bed as 

 this skull, and also determined the age of the formation as belonging to the Equus beds. He afterwards referred to 

 the skull, in Am. Nat., Vol. xxiii, p. 660, as "only found in the TicJioleptus formation of Kansas." This was a lapsus 

 calami which had escaped his notice until after the above was in type, and, at his request, it is hereby corrected. 

 His figures, PL xxxi, were reproductions of three photographs made in Kansas. The photographer had placed the 

 broken left canine-molar upside down In the right (the wrong) alveole. — J. L. 



