1048 
MR. J. W. HULKE ON THE OSTEOLOGY 
Shoulder girdle and forelimb. 
Sternum. The breast-bone is broad and shield-shaped (Plate 73, st.). Its two 
halves are so inclined that they make a blunt median angle or ridge along the inferior 
surface, which starts from the bottom of a deep notch that indents the anterior 
border. The lateral margins bear in front the articular surfaces for the coracoids 
comprising a large segment of a circle. The chord of this in the fully-grown skeleton 
shown in the accompanying sketch is now 30 millims,, but originally it measured 
somewhat more as it is somewhat mutilated posteriorly. Behind the coracoid surface 
are the marks of attachments of ribs. Of the number of these we have as yet no 
certain information. 
Coracoid (Plate 73, c.; and Plate 79, fig. 1).—This is a flat bone of a simple, rudely 
crescentic shape. Its curved border in the articulated skeleton, mesial, is adapted to 
the corresponding surface of the sternum. Its outer border, much stouter than the 
mesial, consists of an articular part in front, and of a deeply incurved non-articular 
part behind. The articular part is subdivided into a thinner anterior segment firmly 
articulating with the scapula, and a stout expanded posterior part—the coracoid 
component of the glenoid fossa. In well-preserved examples a small chink passes a 
short way into the body of the bone from the point where these two sub-divisions 
of the outer border meet, and just in front of this fissure is a perforation as in 
Iguandon Mantelli. The width of the fully-grown coracoid represented in Plate 73, c., 
measured from the middle of the outer border to the corresponding point in the inner 
border, is 45 millims.; and the length of the glenoid surface is 27 millims. 
Scapula (Plate 73 ; and Plate 79, fig. 1).—This is a long, thin, narrow, slightly 
recurved bone, having a general likeness to that of Iguanodon Mantelli. Its dorsal 
end, in uninjured specimens, is expanded antero-posteriorly, its shape is not symme¬ 
trical, the backward extension being greater. The anterior border is sinuous, convex 
in its dorsal, and concave in its ventral half; and near the ventral end is an acromial 
projection, a repetition on a small scale of that shown in the scapula referred to 
I. Mantelli in the collection of J. B. Holmes, Esq., of Horsham, figured by R. Owen 
in his “Fossil Reptilia of the Wealden Formation, Monograph Iguanodon,” t. xiv. 
From this projection a ridge curves upwards and backwards across the outer surface 
ending at the upper or posterior lip of the glenoid fossa. The outer surface below 
this ridge is depressed, whilst that above it is slightly convex. The posterior border 
is slightly concave. At about two-thirds of the distance between the dorsal end and 
the glenoid fossa a slight projection breaks the otherwise regular curve of the posterior 
border (Plate 73). The ventral end of the scapula presents in front a relatively thin 
part suturally joined to the coracoid, and behind this a smooth articular part which 
with the corresponding part of the coracoid composes the glenoid fossa. The length 
of the scapula of an immature individual in my collection (No. 98 Cat., Coll. Hulke) 
(Plate 79, fig. 1) is 86 millims., being nearly that of the humerus ; the width of its 
