134 



DINOOERATA. 



The most, marked cliaracter of these hones in the Dinorernta is that 

 they are flat aiul liorizontal, as in the Artiodactyls, and not vertical, as in 

 the Proboscidians, and tlie Perissodactyls. Tlie first bone of the series, or 

 the pre-sternmn, is compressed, pointed in front, and, at tliis end, has two 

 distinct facets for the first pair of ribs. Tliis bone is shown in Phxte XL, 

 figures 1, 2, and 3. 



The bones wliicli folh)w, and compose the meso-sternum, are broad 

 and flat, somewhat constricted near the middle, with the ends more or 

 less convex. The anterior ends are usually strongly convex, while the 

 posterior extremities may be nearly flat. 



Two examples of these median sternal bones are shown in the same 

 Plate, figures 4-9, as well as in the woodcut belo\\^ 



FiucRE \3?,. — Sternum cif Dinorerns miralih, Miirsli; top viuw. 



One-flftli natural size. 



The last sternal bone of the series, or the xiphi-sternum, is also broad 

 and flat, but has the posterior extremity pointed. This bone is shown in 

 figures 10-12, of the same Plate. 



The surface of all the sternal bones is quite rugose, and the 

 extremities are deeply pitted fiir union with the cartilage that held them 

 in position. 



No indication (_)f clavicles has been observed. 



