CARNIVORA. 615 



The milk dentition is i ^ c \ in ^ (except in the Felidae 

 in which the deciduous molars are ^). The first deciduous 

 molar dm 1 is displaced by p 2 of the permanent dentition, 

 dm 2 is displaced by y> 3 but resembles p 4 (carnassial in the 

 upper jaw), dm 3 is displaced by 2? 4 but resembles m 1 of 

 the permanent dentition.* P 1 of the permanent dentition 

 which has no deciduous predecessor and the anterior molar 

 appear before any of the deciduous molars are shed. 



The paroccipital process of the exoccipital projects either 

 behind the bulla (Ursidae) or is closely applied to its hinder 

 surface (Felidae, Viverridae). The mastoid process of the 

 periotic is usually rather weakly developed. The opening 

 for the carotid canal is either at the front end of the foramen 

 lacerum posterius, or a little way in front of this on the inner 

 side of the bulla. The condylar foramen for the hypoglossal 

 may either be behind the foramen lacerum posterius or within 

 its lips (Felidae). There is a postglenoid foramen for a vein 

 just behind the glenoid cavity except in the Viverridae and 

 living Felidae. The alisphenoid canal is present in Ursidae, 

 and Canidae, and Viverridae, but absent in Mustelidae, 

 Felidae, and Hyaenidae. In the older extinct Felidae, how- 

 ever, both alisphenoid canal and postglenoid foramen are 

 present, and the condylar foramen opens behind the foramen 

 lacerum posterius. 



The orbit is not closed behind but the frontals carry post- 

 orbital processes. The nasals are well developed. There is 

 often a well-marked sagittal crest at the union of the parietals. 

 The jugal is strong and the palate is completely ossified. The 

 tympanic forms a flat or inflated bulla and may or may not be 

 prolonged below the external auditory meatus. The mandible 

 has a coronoid process, and the glenoid articulation of the 

 lower jaw is transversely directed, thus restricting the motion 

 of the jaw to the vertical plane. 



The dorso-lumbar vertebrae are usually twenty in num- 

 ber. The clavicles are always reduced and sometimes absent. 

 The humerus may or may not have an entepicondylar fora- 

 men, and the ulna and fibula are distinct. The scaphoid 



* It has been suggested that we have to do here with an overlapping 

 of the premolar and molar series, similar to that suggested for the Marsu- 

 pials (p. 530). 



