CLASSIFICATION. 617 



bulla, and the mastoid process is inconspicuous or absent ; 



the condylar foramen opens within the margin of the foramen 



lacerum posterius and the postglenoid foramen is absent ; 



the alisphenoid canal is absent. The opening of the carotid 



canal in the Felidae looks into the foramen lacerum posterius, 



but it and the foramen lacerum medium are very minute in 



accordance with the small size of the internal carotid artery. 



In other Aeluroidea the carotid canal is a groove at the side 



of the bulla, and the foramen lacerum medium is better 



marked. The molars are reduced ; there is a short caecum ; 



the OS penis is small or absent. Cowper's glands are present. 



The Cynoidea include the Canidae. The bulla is inflated, 



but the internal septum is very incomplete. The lower lip 



of the external auditory meatus is longer than in the cats. 



The paroccipital process is applied to the back of the bulla, 



but its end is free. The condylar foramen is distinct from 



the foramen lacerum posterius and there is a postglenoid 



foramen. The alisphenoid canal is present and the posterior 



opening of the carotid canal looks into the foramen lacerum 



posterius. The molars are less reduced, and the blade of the 



upper carnassial has two cusps. The caecum is folded, the 



OS penis is present and grooved, and the male is devoid of 



Cowper's glands. 



The Arctoidea include the Ursidae, Procyonidae and 

 Mustelidae. The bulla is without a septum and usually 

 flattened ; there is a considerable lower Up to the bony 

 auditory meatus. The paroccipital process stands behind 

 and clear of the bulla ; the mastoid process is prominent. 

 The condylar foramen is distinct from the foramen lacerum 

 posterius and there is a postglenoid foramen. The ali- 

 sphenoid canal is absent except in Ursus, Melursus and 

 Aelurus, and the posterior opening of the carotid canal is 

 placed on the inner margin of the bulla behind the foramen 

 lacerum posterius. The molars are as in the dogs but the 

 crowns are broad and tuberculated, and the carnassial teeth 

 differ (except in Mustelidae) from those of the other two 

 sections ; there is no caecum ; the os penis is large and not 

 grooved ; Cowper's glands are absent and the prostate is 

 small ; there are always five completely developed toes on 

 each foot. 



