592 THE BEIDGEE EPOCH. 



lopJiodon cornutus, and considerable larger than those of U. robustum and U. 

 mirahile. The occipital condyles are not larger than those of the elk, Cervus 

 canadensis. Their anterior inferior angles are separated by a triangular fossa 

 of the basioccipital bone. This bone is expanded posteriorly, but naiTOws 

 forwards, and is prominent and rib-like where it joins the basisphenoid. 

 There is a short paroccipital process, which is anterior to the external part of 

 the occipital condyle, its internal border rising from the condyloid foramen. 

 Its anterior base, together with the other parts of the exoccipital bone, is closel}^ 

 adherent to the posstympanic process, which forms with it a large trans- 

 verse process behind the auricular meatus. The posttympanic element in 

 this pi'ocess is much the larger, and projects further externally, where it 

 presents a narrow edge. In this respect it differs much from the Loxolo- 

 pJiodon cornutus and Eohasileus fiircatus, where the external face of this 

 process is wide and otherwise characteristic (See plates XXXIII and 

 XXXVII). The base of the postglenoid process is not so extended trans- 

 versely as that of the posttympanic, and is well separated from it. Its out- 

 line is that of one extremity of an ellipse. The glenoid surface has a con- 

 siderable transverse extent in consequence of the sudden expansion of the 

 zygoma behind. Its external extremity is marked by a low tuberosity. 

 The aui'icular groove is bounded below inwai-ds from the internal base of 

 the postglenoid process by an external extension of the os-petrosum. It is 

 fragile and bears on its inferior face a short process, perhaps the stylohyal. 

 The pterygoid process of the sphenoid originates opposite the anterior border 

 of the posterior alisphenoid foramen. The latter is large. Its superior 

 border is continued as a ridge backwards and a little outwards, and over- 

 hangs the foramen ovale. This foramen is smaller than the alisphenoid, 

 and is a narrow oval, looking outwards and forwards. It is situated .015 M. 

 external to the anterior apex of the foramen lacerum anterius, and a short 

 distance within the small internal glenoid tuberosity above mentioned. The 

 condyloid foramen is round and large, and is situated near the anterior 

 border of the basioccipital, where the posterior border of the foramen 

 lacerum posterius is excavated for the jugular vein. There is a small and 

 thin- walled otic bulla. There are no postglenoid nor supraglenoid foramina. 



