126 THE DESEADO FORMATION OF PATAGONIA 
Coresodon Ameghino 
Coresodon Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 630. 
Coresodon Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 459. 
Coresodon Gaudry in part, 1908, Anal. Palaeontologie, t. 1, p. 46. 
In this genus, the pattern of the upper molars is essen- 
tially the same as in Proadinotherium, and they are of the 
same hypsodont character, and with roots. I can now 
find only the fact that in Coresodon the teeth are more 
compressed and somewhat more hypsodont, as a feature 
by which to distinguish this genus from Proadinotherium. 
Gaudry figures the front of a lower jaw under the name 
Coresodon which lacks the caniniform incisors. I have 
doubted the association, but should it prove correct, then 
this genus would be markedly different in that respect. 
Two species have been described, C. scalpridens, and C. 
cancellatus, both of which I consider the same. 
Coresodon scalpridens Ameghino 
C. scalpridens Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 630. 
C. scalpridens Amegh., 1897, Bol. Inst., Geog. Argen., t. 18, p. 459. 
C. cancellatus Amegh., 1901, Bol. Acad. Nac. Cienc. Cordoba, t. 16, p. 374. 
Of this species we found two specimens, one containing 
the three lower molars, the other the second lower molar 
3 
seat il SS) hes) CS 
A 
B 6; D 
Fig. 82. Sections of second lower molar; A, top; B, 4mm. down; C, 10 mm. down; 
D, 18 mm. down—natural size. 
only. In establishing C. cancellatus, Ameghino says it is 
of the same size as C. scalpridens, but distinguished by the 
basin in the upper molars being narrower, the internal 
fold not being bifurcated, and by the absence of islets of 
