1S70.] ^ ' *^ [Cope. 



bone expanded at the extremities in one plane distally, so as to be as wide 

 as long. In the present individual it is crushed by pressure, so that its 

 thickness is not readily determinable. Its external surface rises into a 

 crest medially at the narrowest portion, which continues to the lateral 

 angle of the proximal end, following parallel to one of the borders. 

 A moderate thickening exists on the opposite side a little beyond the ex- 

 tremity of the crest. Strongly rugose strise extend to the edges of the 

 articular faces. An oval rugose muscular insertion exists on the least 

 prominent of the distal angles, and not on a process as in G. propyUwn. 



A bone which from its analogy to the radius of the last named species 

 I suppose to be that bone, accompanies the others. It is flat, truncate 

 proximally and with nearly parallel borders on the proximal half. Distally 

 it is obliquely expanded, the outline forming a segment of an ellipse whose 

 axis is oblique to that of ihe bone. Its extremities are rugose-striate. 



One carpal remains : it is a quinquelateral bone, one side being marginal 

 and concave. Perhaps it is the intermedial. There are several elements 

 which are probably metacarpals. The general structure of the whole limb 

 may be determined from these and from the numerous pJialunges. 

 The former are flattened and with oblique extremities ; the latter more 

 cylindric, with a transverse truncation. Both have a median contraction, 

 which becomes less marked in the distal ones ; these are also more cylin- 

 dric, entirely so at the distal extremities, which are concave. All of 

 these element are rod-like, much more slender than any of those figured 

 by Cuvier or Leidy. Those immediately following the metacarpals are 

 flattened, but thickened distally. 



The number of digits cannot be readily determined, but four may be 

 certainly distinguished. The general similarity in construction of the 

 manus to that of a Cetacean mammal is noteworthy. 



Measurevients. M. 



Length suspensorium (anteriorly) 0.111 



Width " medially 031 



Quadrate, greatest length 099 



" width of ala 066 



' ' thickness behind 03 



" length distal extremity 043 



Pterygoid, length six alveoli 055 



Anterior dorsal, length centrum 059 



" " width cup 0515 



'« " depth " 038 



" " expanse poster, zygapophyses 0395 



" " " diapoi)hyses 091 



" " width neural canal 0185 



" " depth " Oil 



Posterior " " ball 049 



" " width " 0425 



" " length centrum 0555 



" " expanse diapophyses 088 



A. p. S.— VOL. XI — 45e 



