1873.] HTJLKE ANATOMY OF HYPSILOPHODON FOXII. 527 



cess ; from that of Scelidosaurus Harrisoni it differs in the smaller 

 expansion of its dorsal end ; and from that of Hylceosaurus in the 

 absence of the stout acromial ridge which marks the bladebone of 

 this reptile ; whilst to the stupendous scapula of Geteosaurus oxoni- 

 ensis my immature bone has a general likeness. 



The Coracoid (fig. 2, c) is a thin, flat, subsemicircular bone. It touches 

 the scapula, but it has slipped a little backwards from it. Its scapular 

 border is straight. The glenoid border is the stoutest part of the 

 bone. Between it and the longer straight scapular border is a small 

 notch, and between the posterior glenoid lip and the sternal margin 

 is a large deep incurve. The sternal margin is thin, and its outline 

 is an arc. In an older individual, the bones of which were harder 

 and the matrix better adapted to preserve them, this arc in curve 

 and in length agreed with the corresponding border of an adjacent 

 sternum. The coracoid of this individual was also pierced by a 

 foramen near the union of the glenoid and scapular borders, of 

 which only a trace is discernible in my squeezed immature bone. 



Sternum. — A thin shield-like bone, pressed quite flat, lying close 

 to the coracoid, was probably the sternum. It broke to bits with 

 the block of clay in which it was imbedded, during my efforts to 

 extract it from the cliff. The same bone, or rather its anterior 

 moiety, in another individual, here also associated with the coracoid, 

 had a semirhomboidal form. The front or intercoracoid angle was 

 truncated and emarginate ; I roughly judged its length to nearly 

 equal one third of the width of the coracoid, measured between the 

 sternal and glenoid borders. The coracoid margin of this sternum 

 agreed in the form and extent of the curve with that of a near- 

 lying coracoid. Mesially, the lateral halves of this sternum in- 

 cluded a large angle, the ventral surface of which was smooth and 

 keelless. 



Humerus (fig. 2, d). — The left arm-bone lies parallel with the front 

 border of the bladebone, and partly hidden by it. Its length, 3*4 

 inches nearly, equals that of the bladebone. The proximal end bears 

 a subhemispherical articular head (e), placed nearly in the middle, 

 and prolonged upon the dorsal or anconal aspect of the bone. A large 

 crest marks the radial border of the shaft near the proximal end. 

 The shaft itself is somewhat twisted. The ventral surface of the 

 distal end is hidden. 



Forearm. — The greatest part of both bones of the forearm could 

 not be preserved. The ulna, for its size, has, I think, as large an 

 olecranon as that represented in Prof. Owen's plate of this bone in 

 Iguanodon, issued by the Palseontographical Society last year. The 

 radius is much broader at the wrist than the ulna, and it forms the 

 principal support of the manus. The radius of a mature individual 

 I found to be 4-87 inches long, the ulna slightly more ; and the 

 humerus was 5 - 75 inches in length. 



Manus (fig. 3). — The bones of the fore foot, together with the distal 

 ends of the radius and ulna much crushed, were lying disconnected 

 and confusedly in the clay, near the larger mass containing the 

 shoulder-blade and coracoid. Two carpals are discernible, one of 



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