272 PATAGONIAN EXPEDITIONS : PALEONTOLOGY. 



edge of the nasals and forming a considerable part of the roof of the broad 

 nasal chamber. The zygomatic process of the maxillary is rather short, 

 but is given an appearance of prominence by the depth of the preorbital 

 fossa ; the infraorbital foramen is small. The lachrymal is like that of 

 Hapalops except that the foramen is narrower and more slit-like. The 

 palatine processes of the maxillaries are remarkable for their great expan- 

 sion in front of the molariform teeth and for the great depth of the 

 V-shaped notch which lodges the premaxillae ; between the molariforms 

 the palate is rugose, but only moderately convex. The palatines are short 

 and together form a triangular plate, with sharp apex directed forward ; 

 the posterior nares are very broad and their front border is behind the 

 last tooth. 



The mandible (Plates LV, figs. \d, 2; LVI, 4, 4^) has a short, but ex- 

 tremely thick and heavy horizontal ramus, with strongly convex ventral 

 border ; the symphysis is short and steeply inclined and the chin is abrupt ; 

 the predental beak is very short, deeply constricted at the base by a notch 

 on each side for the upper caniniform, and of triangular shape, contracting 

 to a point anteriorly ; as a rule, the dorsal surface is but moderately con- 

 cave and the lateral borders are depressed and everted. In one specimen, 

 however, which is apparently referable to this species (A. M. N. H., No. 

 9,575, Plate LVI, 3, 3*2) the beak has quite a different appearance; the 

 notches for - are unusually large and deep and, seen from above, the 

 beak is cordiform, rather than triangular, and is more concave, with mar- 

 gins less everted. An apparently constant difference of the present species 

 from E. ingens is in the mental foramina, of which a single conspicuous 

 one is found on each side of the base of the beak. The coronoid process 

 is higher and more erect, less inclined and recurved than in E. extermis, 

 but the angular process is considerably shorter. 



MEASUREMENTS. 



Type. No. 9,24.1. No. 9,575. No. 15,314. 



Occiput, height .043 



" width at base .058 



Skull, width at postorbital constriction .038 



" " over J- 042 



Palate, width at 1 026 



" " " L 016 



Mandible, length from condyle 113 .115 .119 



" angle .128 



