408 HIPPOPOTAMUS. 



to the precurved angle at the base of the ascending ramus 



a. Both these processes are broken off in the fossil 

 lower jaw of the Hippopotamus major preserved in the 

 Grand Ducal cabinet at Florence, and figured by Cuvier 

 in pi. iv. of his chapter on the Fossil Hippopotamus. (Op. 

 cit.) Our English specimen fully confirms the difference, 

 which the Florentine jaw left somewhat doubtful, in the 

 degree of forward curvature of the process, a, which 

 curvature is more rapid and extensive in the recent than in 

 the fossil Hippopotamus. The lower contour of the hori- 

 zontal ramus begins to be convex almost immediately ante- 

 rior to the above curvature in the recent species ; in the 

 fossil it continues concave to the alveolus of the canine tusk, 



b. The coronoid process, p, is more vertical in the fossil ; 

 it inclines forwards before curving back in the recent 

 species. Of the narrower interspace between the two 

 rami and the sharper angle at their anterior union, so 

 well marked in the Florentine jaw, the Norwich specimen 

 does not afford evidence ; but it shows the same equality 

 of breadth of the jaw along the outside of the molar 

 series. The swelling-out to form the socket of the canine, 

 commences, as in the Italian specimen, anterior to the 

 premolar tooth, p 2, and not, as in the African Hippopo- 

 tamus, opposite the middle of the molar series.* 



Traces of the socket of the first premolar, p 1, still re- 

 main in the fossil ; the second premolar, p 2, is relatively 

 larger, and is separated by a wider interspace from the 

 third than in the recent Hippopotamus ; and the oblique 

 ridge on the inner surface of the crown is more developed 

 in the fossil. The first true molar, m 1, presents a basal ridge 

 on the outside of the hinder lobe, and a tubercle at the base 



* Compare fig. 162 with the same view of the lower jaw of the recent Hippo- 

 potamus in the ' Ossemens Fossiles,' torn, cit., 'Hippopotame vivant,'pl. ii. fig. 4. 



