R. S. Lull — Primitive Pecora in Yale Museum. 115 



Hypertragulus ordinatus Matthew. 



This species is based on a complete lower jaw (No. 

 13011, A. M. N. H.) from the lower Rosebud beds on 

 Porcupine Creek, South Dakota. It is larger than the 

 type species of the genus, H. calcaratus, and about equal 

 to H. liesperius. It may be distinguished from either by 

 the following characters : Closing of diastema between 

 P 2 and P 3 , and great reduction of diastema between C± 

 and Pj ; increased length of diastema between caninif orm 

 P x and P 2 , so that general proportions of jaw are about 

 the same ; molar crowns more hypsodont than in H. lies- 

 perius, about as in H. calcaratus ; P x and P 2 shorter and 

 proportionately higher than in the John Day species but 

 less reduced than in that from the White River. In the 

 upper Rosebud this species is replaced by Blastomeryx. 



Hypertragulus minutus, sp. nov. 



Holotype, Cat. No. 10545, Y. P. M. Upper Oligocene (upper John Day), 

 Oregon. Fragments of upper and lower jaws and teeth. 



A very small form, apparently Hypertragulus. Dis- 

 tinguishable from H. liesperius mainly by its small size. 

 Cingula well developed, but metastyle of M 3 much 

 reduced, not forming the conspicuous "heel" of lies- 

 perius. Its measurements are, compared with those of 

 liesperius : 



H. minutus H. hesperius Yale spm. 

 mm. mm. 



Length, M 1 to M 3 14 20 



Length, M 3 5.8 8.5 



Width, M 3 5 8.5 



Leptomeryx obliquidens, sp. nov. 



Holotype, Cat. No. 10541, Y. P. M. Oligocene (Protoceras beds), Her- 

 mosa, South Dakota. Poorly preserved skull and jaws, with entire series 

 of cheek teeth. 



Distinguishing characters. — Large size; superior 

 molars obliquely set ; temporal ridges meeting at a wide 

 angle to form the sagittal crest which is sharp and thin 

 throughout its preserved length; bullae laterally com- 

 pressed, elongated oval in shape. 



