506 HARRY GOVIER SEELEY ON THE 



such worn fragments, to estimate aright the differences of size and 

 stoutness. 



The isolated ends exhibit corresponding differences of size. The 

 smallest measures ^ inch from within outwards over the proximal 

 articulation, while the largest specimens are T 9 ^ inch in that mea- 

 surement, and have a corresponding thickness in the shaft. In 

 all, the external proximal surface terminates in a sharp margin 

 on each side, is flattened and wide — ^ inch wide in the larger spe- 

 cimens, and less than -f^ inch wide in the small bones. Usually 

 this area is somewhat concave below the articulation. The articular 

 surface itself extends over the whole of the proximal end. 



A medium-sized distal end of a left femur (PL XXVII. figs. 9, 10, 

 11) I refer to Enaliomis SedgwicM. The fragment is about an 

 inch long, subovate where fractured proximally, being T 5 ^- inch in the 

 greatest oblique measurement from before backward, and less from 

 side to side. The shaft becomes compressed on the inner and pos- 

 terior side towards the distal articulation, above which its section 

 would be subtriangular ; for the inner margin of tbe anterior aspect 

 is a somewhat sharp ridge more marked than in the Diver, which 

 is prolonged into the inner distal condyle. The outer condyle is 

 much the larger, and extends about T ^- inch further distally than 

 the other. The intercondylar space in the fossil has not so great 

 an antero-posterior compression as in the Diver ; and the inner con- 

 dyle is rather deeper than in that type. The width over the con- 

 dyles is T 9 g- inch ; the depth of the outer condyle is nearly T 7 ^ inch. 



A larger distal end of a right femur (PL XXVII. fig. 12), which I 

 regard as that of Enaliomis Barretti, more than an inch long, is 

 nearly f inch wide over the articulation ; and the whole bone is 

 proportionately larger. The condyle is relatively larger and deeper 

 than in the other species, and the anterior channel between the 

 condyles is relatively deeper. Another specimen, in better preserva- 

 tion, I noticed in the collection of "VV. Keed, Esq. I shall be quite 

 prepared to find that the femora which have passed through my hands 

 belong to more species than I have indicated ; but, in the absence 

 of other evidence, I do not see my way to giving them any useful 

 definition. 



The Tibia. (PL XXVII. figs. 13-21 ; PL XXVI. figs. 24, 25.) 



The remains of tibiae comprise two proximal ends of right tibiae in 

 the AVoodwardian Museum, and one in that of Mr. Reed, and a left 

 one in the collection of Mr. Jesson, all of which have a moderate 

 patelloid process, which is more developed than in the Gannet, but 

 makes no approximation in length to that of the Diver. There are 

 also in Mr. Jesson's collection two specimens of right and left proxi- 

 mal ends of the smaller of the two forms of tibiae, which are imper- 

 fectly ossified and have no trace of a patella, but terminate in rough 

 cartilaginous surfaces. These bones seem to be young specimens of 

 Enaliomis Sedgwicki, though the remains are not inferior in size to 



