480 Bulletin American Museum of Natural Histoty. [Vol. XIX, 



simple. (2) The molars are proportionally wider trans- 

 versely, especially at the summits of the cones. (3) The 

 posterior heel of m-' is wider transversely, and is more dis- 



Fig. 4. -Platygonus veins Leidy. Amer. Miis. No. 2724. X J. 



/ m.2 '"-? 



Fig. 5. — Platygonus ic.xanus. Type. Amer. Mus. No. 10702. X \. 



tinctly separated by a cross valley from the posterior crest of 

 the tooth. (4) The canine is proportionally much thicker 

 anteroposteriorly than in P. vet us, as indicated by the 

 alveolus. (5) The backward extension of the palatines is 

 much greater than in any species in which this character is 

 known, the anterior border of the palatal notch being situ- 

 ated nearly three times farther back of the posterior molars 

 than in P. rex. 



