ivith Descriptions of Neiv Species. 



237 



dorsals, and the proximal parts of the first three ribs 

 articulated and partly enclosed by matrix. The skull and 

 jaws, which have not been separated, show a similarity to 

 P. macrostegus, but the differences are too great and too 

 important to identify it mth that species. The skull is 



Fig. 4 A. 



Fig. 4. — Promerycoclioerus marsM, sp. nov. Holotype, Cat. No. 10999, 

 Y. P. M. A, right lateral view of skull and jaw; B, right half, superior 

 view. X ^• 



slightly longer and much more robust than in the latter. 

 In this specimen the orbits are not so high, are smaller, 

 and more nearly round ; malar is much wider and heavier ; 

 infra-orbital foramen smaller; nasals project farther 

 forward ; face much deeper above the premolars ; mandi- 

 bles heavier and masseteric fossa very much deeper; 

 incisive foramina much closer together, larger, of differ- 



