55 



ulna. The latter however has a small convexity in the middle 

 of its outer margin under the semicircular olecranian process — 



Length of cubitus ... . 



Width at base, including olecranian apophyse. 



Width at neck . 



Length of the radius , 



Width at top 



Width in the middle ... 



The carpal bones are in the E/iphysetes not so far sepa- 

 rated from each other by cartilage as in the Catodon. 

 They are seven in number ; viz. : two linear transverse bones 

 and five of a flat, round, irregular shape, a small hexagonal 

 one of which is placed between one of the transverse bones 

 and the metarcarpal bone of the thumb. This trans- 

 verse carpal bone is sub-triangular, and placed at the termina- 

 tion of the radius. The remaining thin transverse bone is 

 trapezoidal and situated between the base of the ulna and the 

 two outer carpal bones. The forefinger has also two large flat 

 carpal bones, placed between the corner of the radius and the 

 metacarpal bone of the fore-finger. Of these two carpal bones 

 the one nearest the radius is pentagonal, and the other hexa- 

 gonal. From one side of the hexagonal bone proceeds the 

 metacarpal bone of the third finger. The largest carpal bone, 

 which is subpentagonal, lies between the trapezoidal transverse 

 carpal and the metacarpal bone of the fourth finger, while a 

 small subquadrangular carpal bone joins the outer edge of the 

 linear trapezoidal carpal with tha metacarpal bone of the little 

 finger. This position of the carpal bones among themselves, 

 so widely different from the disposition of them in the pectoral 

 fin of the true sperm whale, is nevertheless certain; but the way 

 in which they are connected with the metacarpal bones is not so 

 certain, as only the bones of the thumb and fore-finger, part of 

 the right fin, were found in situ. Almost all the smaller bones 



