314 SCOTT. [Vol. XI. 



whole width of the glenoid cavity, nor, as in the cavicorns, 

 is it confined to the postero-internal angle, but is placed 

 somewhat internal to the median line. The posttympanic 

 process is very short and slender and is closely applied to the 

 mastoid portion of the periotic. In all the recent Pecora there 

 is a large opening between the auditory meatus and the in- 

 ferior margin of the squamosal for the passage of nerves and 

 blood-vessels ; in Leptomeryx, Hypertragidiis, and the recent 

 tragulines no trace of this opening is to be found. Protoceras 

 agrees with the latter in this respect, the auditory meatus 

 being in contact with the squamosal in front, behind, and to 

 some extent, above. 



The jugal is heavier than is usual in existing ruminants ; its 

 posterior branch extends backward beneath the zygomatic pro- 

 cess to the outer edge of the glenoid cavity. Beneath the orbit 

 the jugal projects outward into quite a broad horizontal shelf, 

 corresponding to the prominence of the supraorbital border. 

 The postorbital process is short, and deeply notched to receive 

 the anterior end of the zygomatic process. The orbit, which is 

 completely encircled by bone, is bounded behind more by the 

 postorbital process of the frontal than by that of the jugal. 

 The vertical portion of the jugal, which articulates with the 

 maxillary, is rather small and is not much expanded upon the 

 face ; this is due to the rather low position held by the orbit, 

 which is not so much elevated as in the typical deer. This 

 has an effect also upon the conformation of the posterior 

 nares. The lachrymal, which is quite large, is not depressed 

 to form a pit or fossa, as it is in so many of the recent deer 

 and antelopes, as well as in the oreodonts. It has a limited 

 suture with the nasal, instead of being separated from it by a 

 vacuity, such as occurs in Leptomeryx, Hypertragidtis, and most 

 of the existing Pecora. Short as are the nasals, they are long 

 enough to show indications of such a fontanelle, had it existed. 

 No great taxonomic value can be attached to this character, as 

 within the limits of the same family we may find some genera 

 with and others without it, as, for example, in the oreodonts, 

 Merychyiis and LeptaiicJienia, with its allies, have the vacuity, 

 the other genera are without it. 



