258 ON PLATYGONUS COMPRESSUS : 



inet. Not only was the request granted, but, with the generosity 

 of a scientific spirit, the entire collection was placed at my dispo- 

 sal, that it might be rendered more accessible to our comparative 

 anatomists. Mr. Snyder has also promised to procure such other 

 specimens as may be found in his vicinity. It is also hoped that 

 in a short time casts of the bones already obtained will be ready 

 for distribution to the learned societies of our country. 



Among the specimens now in my possession were detected re- 

 mains of the following animals : — Plattjgonus compressus (the sub- 

 ject of the present memoir), Hyops depressifrons (a new animal 

 allied to Dicotyles), and a new species of Procyon. From another 

 fissure were obtained teeth, indicating two other new genera, which 

 are referred to in the notice quoted above. 



We now proceed to the description of the separate bones of the 

 first-named animal, commencing with the teeth. 



Dentition. 



By carefully picking away the cement which envelops the ante- 

 rior part of the fragment (figs. 1,2), a small external incisor was 

 discovered : the distance of this tooth from the superior canine is 

 given in the table of measurements at the end of the descriptive 

 part of this memoir. The bone is so much mutilated, that it is 

 impossible to determine whether there were two or three superior 

 incisors on each side ; although, from the affinities of the animal, 

 there were doubtless three. In the form of the tooth there is noth- 

 ing peculiar ; it has a rounded mammillary crown, scarcely acute 

 at the summit. 



The superior canine (figs. 9-11) is very much compressed, 

 pointed, and curved ; the anterior edge almost sharp ; the posterior 

 acute and trenchant ; the external face (fig. 9) slightly more con- 



