508 HARRY GOVIER SEELEY ON THE 



species, and is ^ inch wide. It is ovately rounded proximally, 

 strong, compressed from front to back, and extends a little out- 

 ward and forward beyond the shaft, where it terminates in a sharp 

 ridge, which is directed forward and continued a short distance 

 distally down the shaft. On the inner side there is no ridge on the 

 patella ; but a sharp angle extends from its base down the shaft. 



The distal end of a right tibia of this species in the Wood- 

 wardian Museum is well preserved (figs. 16, 17, 18). The shaft 

 is much compressed from front to back, and set on to the small 

 distal articulation so as to be flush with it behind. The shaft 

 measures T 5 ^ inch from side to side at about -| inch from the distal 

 end, and is nearly ^ thick. The distal articulation widens to T 7 ^- inch ; 

 posteriorly it extends up the shaft for | inch, forming a broad shal- 

 low channel margined laterally by two strong ridges which are con- 

 tinued round into the condyles (fig. 18), forming their external mar- 

 gins, and defining the lateral regions of the lower part of the shaft. 

 The convex base of the inner side of the shaft is more than | inch 

 wide, while the base of the inner side, which is rounded superiorly, is 

 y^- inch wide. The anterior surface (fig. 16) of the shaft consists of 

 an external half, which is deeply excavated, and an internal part which 

 is somewhat thickened, and at its base, just above the middle of the 

 articulation, gave off a slight process which appears to have been 

 directed over the channel. The margins of the articulation are ele- 

 vated ; but the space between them is concave from side to side. The 

 internal condyle is rather the larger of the two. 



Fibula. (PI. XXVI. figs. 26, 27.) 



This identification is less evident than are the others. But as no 

 bone of the fore limb, or scapular arch, or sternum, has hitherto 

 been recognized among the bird-remains from the Cambridge Green- 

 sand, the only bone left to be identified which could unite to a slen- 

 der shaft a moderately expanded proximal end, is the fibula. The 

 bone is, relatively to the tibia, much larger than in existing birds ; 

 but since Professor Marsh finds this to be a characteristic of the 

 fibula in fossil birds from the American Cretaceous deposits, it is 

 probable that Enaliornis had a community of structure with the 

 transatlantic genera in this particular as well as in general affinities. 

 Two specimens have been preserved in the Woodwardian Museum, 

 both probably from the left side. The longest is more than an inch 

 long, is compressed from side to side so as to be four-sided at the 

 distal fracture, where it is \ inch wide and less than -^ inch thick. 

 Proximally the shaft becomes wider on one of the narrow sides, and 

 compressed on the opposite side, so that in section it is triangular, 

 and wider in both dimensions than lower down. On what I take 

 to be the inner posterior margin is a slight sharp ridge, which may 

 be an indication of the ridge by which, lower down, the fibula united 

 with the tibia. The proximal end is expanded and articular, sub- 

 triangular, inclined a little inward, and somewhat rounded superiorly 

 from side to side. It measures T 7 g- inch from back to front, and 



