PCEBROTHERIUM — AGRIOCH(ERUS. 



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 axilla?. 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-postcrior curve of the carapace (estimated), . 13 



" 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. 



PCEBROTHERIUM 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 bullae, 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. 



AGRIOCHCERUS 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. 



