268 PATAGONIAN EXPEDITIONS I PALEONTOLOGY. 



teeth which I have regarded as the males; T is hardly larger than in 

 Hapalops and projects comparatively little beyond the line of the other 

 teeth ; in cross-section it is obscurely trihedral, with the base presenting 

 forward, and is very obliquely worn ; ^ and 7 are broad transversely, com- 

 pressed antero-posteriorly, and T is irregularly cylindrical. The jaw has 

 a much less robust horizontal ramus than that of the supposed male, with 

 less convex ventral border ; the predental beak is very broad at the base 

 and hardly at all notched for -. On each side, near the median line, are 

 two conspicuous mental foramina, one above the other, of which the lower 



is considerably the larger. 



MEASUREMENTS. 



No. 9,307. Male (Amegh. Coll.'). 



Lower dentition, length 0465 .047 



" " " 5-_ T 0265 .026 



T , length (i. e., antero-posterior diameter) 0055 .008 



" width (i. e., transverse diameter) 005 



2-, length 007 .007 



" width 0105 



g-, length 0065 .005 



" width 0105 



T , length . 009 



" width oio 



Mandible, length from condyle 130 



to y, inclusive 099 . 1 14 



angle to T , inclusive .122 



depth at 3- 036 .044 



thickness at 3- 021 



height of condyle .062 



" " coronoid -074 



The following measurements of the type-specimen are taken from 

 Ameghino ('89*, 693-4). 



Upper dentition, length 071 & , width 0085 



Lower " " 055 T , length oil 



Upper diastema, length 023 " width 014 



1, length oil Diastema, lower, length 013 



" width oio Lower dentition, length ^_ 031 



i, length 0075 Palate, length 070 



" width 01 1 " width at i 039 



, length 0075 " " between molariforms 026 



" width 012 Skull, length condyle to 1 172 



A, length 0075 " width over 1 062 



" width 01 25 Mandible, length of beak 035 



, length 006 " depth below molariforms . . .035 



