PHBROTHERIUM—AGRIOCH@RUS. 571 
The entosternal plate is as broad as it is long, being about two inches, is short 
pyriform, reaches the border of the humeral scute behind, and encroaches a half 
inch upon the position of the gular scutes. 
The hyosternal plates articulate with the third to the anterior angle inclusive of 
the sixth marginal plates. 
The hyposternals articulate with the sixth and seventh marginal plates. 
The humeral scutes internally are half an inch long, and their anterior border 
externally curves forwards and outwards to the axille. They join the axillary 
and the fourth and fifth marginal scutes. 
The abdominal scutes are two and three-quarter inches long, and join the sixth 
and three-fourths of the seventh marginal and the inguinal scutes. 
ADMEASUREMENTS. 
Inches. Lines. 
Length of the sternum at the middle, ; : ; 8 6 
Breadth to articulation with the marginal plates, . ; 6 3 
Length of antero-posterior curve of the carapace (estimated), , 13 
ise transverse curve from a level of the sternum, . ; 14 
Height of carapace from level of the sternum, : . 5 
CONCLUSION. 
Besides the various remains of Mammalia and Chelonia described or mentioned 
in the preceding chapters, a number of others have been obtained from the same 
locality, of which the following list is a synopsis. 
P@BROTHERIUM WILSONI. § Leidy. 
An extinct species and genus of Ruminants most closely allied to the existing 
Musks or the extinct Dorcatherium, Kawp, of Europe. It was established in the 
Proceedings of the Academy of Natural Sciences of Philadelphia, vol. iii. p. 322, 
for 1847, upon the greater portion of a skull containing nearly all the molar teeth, 
of which those temporary had not yet been shed. The specimen was presented to 
the Academy by Mr. Joseph Culbertson. 
The head is most remarkable, so far as can be ascertained, for the possession of 
the full or normal number of molars, the great narrowness of the face, the large size 
of the auditory bull, and the prolongation of the technical angle of the lower jaw 
into a hook, an approach in resemblance to which among existing Ruminants we 
find in the Camel. 
AGRIOCHGRUS ANTIQUUS. Leidy. 
An extinct species and genus of Ruminants, which is one of the lost links of the 
wide interval between existing members of the family and the very aberrant form, 
the extinct Amplotherium, Cuvier, of the tertiary formations of Europe and Asia. 
