EXPLANATION OF PLATE X. 



Figures i, 2, 3, 4, and 6, natural size. 



ITHYGRAMMODON CAMELOIDES. 



Fig. i. Left premaxillary, inner view. 



Fig. 2. Left premaxillary, outer view. 



Fig. 3. Right maxillary and premaxillary, outer view, premolar, with dotted 

 outline indicating its probable position. 



Fig. 4. The premaxillaries in position (probable), view from above, show- 

 ing size and position of the incisors. Dotted lines indicate the premaxillary 

 spine (estimated). 



PROCAMELUS OCCIDENTAL^ Cope. (See Wheeler's Survey, vol. iv., Plate 

 LXXVII.) 



Fig. 5- Part of right maxillary and premaxillary, showing single incisor 

 with rudimentary alveolus for a second. 



PROTOLABIS ? Cope. (See Wheeler's Survey, vol iv., p. 343.) 



Fig. 6. Right maxillary and premaxillary. (This has never been drawn 

 before, and was kindly lent to us for this purpose by Prof. Cope.) 



CAMELUS BACTRIANUS. Modern camel. 



Fig. 7. Right maxillaries, one half natural size. 



