Leptauchenia minima, sp. nov. 



Represented by numerous remains of a species not larger than a gray 

 squirrel . 



The antero-exterior vertical ridge is more prominent, and overlaps the 

 preceding tooth more extensively than in the other species. The pos- 

 terior superior molar is narrowed behind, and has a small heel column. 

 In the mandible the third premolar is three-lobed, and the first premolar 

 is not' separated from the second by a hiatus. Enamel smooth. The 

 valleys of the anterior lower molars disappear with use more frequently 

 than in some of the allies. 



Me a sure me nts. 



M. 



Length of true molars above (No. 1) 0120 



last " 0050 



Width " " 0030 



Length three inferior posterior molars (No. 2) 0130 



" " last molar 0058 



Width " " " 0025 



Probably the least known species of Artiodactyle. 



Trimerodus cedretjsis. Gen. et sp. nov. 



Char. gen. Molars constructed as in Leptauchenia ; the last premolar 

 three-lobed externally, internally with one, a posterior lobe. Exterior 

 ribs prominent. 



Char, specif. Eirst true molar with anterior and posterior cingulum, 

 and with the inner crescents more elevated on the anterior limb. Last 

 premolar with a broad cingulum within the two anterior lobes. 



Measurements. 



M. 



Length first molar 0060 



Width " " 0055 



Length last premolar 0070 



Width " " 0040 



Size equal to that of Leptauchenia calcarata. 

 Published August 20, 1873. 



