HATCHER : OLIGOCENE CANID^ 75 



men lies at the postero-internal base of the postglenoid process. The foramen 

 lacerum w,edium was situated at the antero-internal angle of the auditory bulla. 

 The foramen ovale and posterior opening of the alisphenoid canal were a little less 

 separated than in modern dogs and opened by a single rather elongate and oval 

 aperture situated external to the posterior extremity of the pterygoid. The ali- 

 sphenoid canal appears to have been small, but long, so that its anterior opening, the 

 sphenoidal fissure and the optic foramen are crowded close together and all occupy a 

 comparatively small space at the base of the pterygoids. 



Measukements (No. 492). 



Greatest length of skull 205 mm. 



Greatest expanse of zygomata, distortion eliminated 119 " 



Length of sagittal crest 95 " 



Height of sagittal crest at point of union with occipital crest 28 " 



Height of sagittal crest above greatest expanse of brain-case 16 " 



Length of zygoma 93 " 



Breadth of cranium at point of greatest constriction 31 " 



Greatest breadth of cranium 58 " 



Expanse of frontals at posturbital processes 43 " 



The Mandible, Pl. XIV., Fig. 2; Pl. XVL, Figs. 2 and 4. 



The lower jaw is not unusually heavy for a dog of the size indicated by the 

 skeleton. The horizontal ramus is perhaps a little deeper than in modern wolves 

 of the same size, but no thicker. The rami are not coossified. The inferior border 

 is very sinuous and posteriorly it is produced into a slender and hooked angular 

 process. The coronoid process is remarkably broad, thin posteriorly and superiorly, 

 but much thickened quite to the summit anteriorly. The condyle is situated 

 slightly above the alveolar border. It is subcylindrical, and with the articular sur- 

 face, broad internally and narrow externally. This surface looks backward rather 

 than upward when the jaw is held in a horizontal position. The masseteric fossa 

 is deep and broad. Anteriorly, inferiorly and posteriorly, it is bounded by promi- 

 nent ridges of bone, developed on the anterior border of the ascending ramus, the 

 postero-inferior border of the horizontal ramus, and that portion of the posterior 

 border of the ascending ramus which gives support to the external portion of the 

 condyle. There are two mental foramina situated about midway between the supe- 

 rior and inferior borders of the ramus. One of these, the anterior, is located directly 

 below the anterior root of P. 2, while the posterior lies below the same root of P.^. 

 The inferior dental foramen is placed near the inferior border and midway between 

 the angle of the ramus and the last tubercular molar. 



