252 TEETIAET VERTEBEATA OF THE FATtrM. 



incisors is probably, as already remarked, a primitive character derived from a 

 Creodont ancestry ; in Prozeuglodon the canine seems to have been relatively larger 

 even than in Protocetus. Another Creodont-like character in the upper jaw is the 

 presence within the posterior upper premolars of large fossae for the reception of the 

 corresponding lower teeth. The pit for the reception of the point of the lower pm. 2 

 is on the alveolar border immediately behind pm. 1. In front of this the pits are 

 on the outer side of the upper teeth, the upper and lower tooth-series crossing as in 

 Zeuglodon osiris (see Stromer, op. cit. p. 67). 



Mandible (PI. XXI. fig. 1e ; text-fig. 80). — The imperfect right ramus of the mandible 

 is preserved, articulated with the type skull. The posterior portions of the coronoid 

 process and of the angular region are broken away, while the horizontal ramus is 

 imperfect anteriorly and has lost most of its ventral border. The condyle is strongly 

 convex from before backwards, the articular surface forming rather more than a 

 quarter of a circle. From the condyle on the outer face of the jaw a strong shelf-like 

 ridge runs forwards for a short distance, dying away in the strongly convex outer 

 surface of the ventral part of the jaw ; when the jaws are closed, the jugal lies in the 

 groove above this projection. The coronoid process is thin and high ; it is imperfect 

 posteriorly, but its anterior convex border is well preserved and in front slopes 

 steeply down to the alveolar border, which, so far as the region occupied by the 

 molars is concerned, is also strongly inclined downwards. The horizontal ramus was 

 comparatively slender, its outer face convex from above downwards, the inner nearly 

 flat; the symphysis extended back to about the hinder border of pm. 2. 



Lower Dentition (PI. XXI. fig. 1 e ; text-fig. 80). — The anterior part of the jaw is 

 incomplete, and its upper border obscured by strongly adherent matrix, so that the 

 alveoli of the incisors, canine, and first premolar are absent or covered up. The first 

 tooth present seems to be pm. 2. This is a double-rooted tooth with a strongly com- 

 pressed conical crown with sharp cutting-edges, the anterior of which is steeper than 

 the posterior. On the anterior edge there are three or four small serrations, while on 

 the posterior there are two accessory denticles of considerable size and a small cusp 

 belonging to the cingulum. The next tooth, presumably pm. 3, is also two-rooted : it 

 is much larger than pm. 2, but the crown is imperfectly preserved ; both its anterior 

 and posterior borders wpre serrated, the posterior serrations being few and large. 

 The next tooth also is badly preserved ; it is smaller than pm. 3, but the posterior 

 serrations must have been larger. Behind these premolars are the sockets of two or 

 three molars, the anterior molar being apparently nearly as large the last premolar. 

 The second molar is just being cut, and there are indications of a third molar behind it. 

 , Vertebral Column (text-fig. 83). — Three anterior cervical vertebrae probably associated 

 with portions of a skull were collected by Mr. Beadnell. These specimens are in a 

 remarkably perfect state of preservation, and have almost the appearance of recent 

 bones. In the atlas (text-fig. 83, A, D) the surfaces for the occipital condyles (cond.) are 



