EINAR LÖNNBERG, THE GENUS POTAMOCHCERUS. 



35 



fuUy described, although it lias received several names, tlie 

 foUowing additional notes on its skull together with a couple 

 of figures of the same to be compared with Major's of the 

 eastern race may be of value. 



The forehead of the skull of P. larvatus is very flat which 

 makes the profile contour straight with some irregularities 

 at the nasal exostoses which appear to be almost better de- 

 veloped than in P. 1. Jiova. The posterior parts of the na- 

 sals are flat with somewhat raised lateral borders and a ten- 

 dency to develop callosities. The anterior portion of the 

 nasals is just as well as in P. 1. Jiova convex and evenly 

 rounded off in joining the premaxillaries. The width of the 



Fig. 3. Skull of a boar ot J'ot<iinoci(arus Larvatus (F. Cuvier) from 

 Marovoay, X. W. INIadagascar. Coll. by W. Katjdern. 



nasals is posteriorly about 39 mm. hut they are narrowed to 

 24 mm. in front which mostly is due to the curving. 



The premaxillary extends rather far backwards, the ver- 

 tical through its posterior end touching p^ (in P. 1. Jiova it 

 passes through p-). The sides of the maxillary are concave. 

 The apophyses above the canines are rather broad with a 

 horizontal antero-posterior diameter of 38 mm. They are 

 directed somewhat backwards so that the vertical through 

 the posterior margin passes through the middle of 2^^» but 

 they do not rise in lieight to the level of the nasal surface, 

 missing it by 11 — 12 mm. They are thus comparatively lower 

 than in adult boars of P. 1. Jiova and their anterior margin 

 is more sloping than in the latter, to judge from Major's figure. 



