52 R- J- Anderson, 



the 9*^ to the 12*^, the groove is in the border, and on the thirteenth 

 it is internal being overlapped by the prominent outer lip of the an- 

 terior margin. 



The groove gets shorter from the eighth rib back. It is 30 cm. 

 long in the 8*^ and only 5 cm. long in the 13'\ 



The anterior and posterior edges of the ribs below the termination 

 of the grooves externally are quite sharp in the lower three ribs the 

 posterior edges being convex and the anterior concave. 



The 9'^ and 10'^ have thick upper edges as far down as the 

 lower third. 



Bos Americanus. 



The narrower character of the ribs, the absence of the grooves 

 in the lower part of the outer surface have been pointed out by 

 Meckel, Cuvier and other anatomists. The absence of the grooves is 

 most remarkable. The anterior margin projects forwards in the 12*^ 

 rib (180 mm. above the lower end). 



The 10*^ and 11*^ have a backward prolongation, the former, at 

 a distance of 110 mm. above the lower end causing the breadth to 

 increase from 22 mm. to 30 mm. The increase in breadth of the 

 second takes place at a point 120 mm. below the lower end. 



Cephalolophus Mergens. 



The distance of the last dorsal transverse process from the first 

 is 185 mm. 



The tangential breadths are given except at the angles, where the 

 radial breadths of the first eight and the tangential of the last five 

 are given. 



The seventh rib is the broadest and bends below the lower angle. 



The radial breadths are but slightly in excess of the tangential 

 breadths beyond the angles, but above i. e. between the angles and 

 the vertebral column the anterior surfaces are broader than the lateral, 

 as we find in many other ungulates. 



The letters have the same signification as the last. 



