OF HYPSILOPHODON FOXII. 
1049 
dorsal end is 26 millims., that of its ventral end is 32 millims., of which 10 millims. 
belong to the glenoid, and 22 to the coracoid segment; but these numbers have only 
an approximate value as the bone has been injured by pressure. Some of the dimen¬ 
sions of the scapula represented in Plate 73, are as follows :—Length from dorsal end 
to acromion 14‘3 centims,, length of glenoid surface 2'8 centims., and that of coracoid 
border about 3 centims. 
Forelimb. —The structure of this is still incompletely known. I have as yet only 
recovered very mutilated remains of it.* 
Humerus (Plate 73; and Plate 79, figs. 1 and 2).—This is nearly as long as the 
scapula. Its proximal end is broadly expanded, convex tranversely on its dorsal 
aspect, and concave in the same direction in the ventral surface. The proximal end 
bears, nearly at its middle, a smooth sub-spherical articular surface from which a 
ridge-like swelling passes some distance down the dorsal surface of the bone. The 
anterior, radial, border swells into a stout crest which renders its outline convex in 
the upper third of the bone. The contour of the posterior border is a hollow curve. 
The shaft seems to be slightly twisted owing to a small change in the direction of 
its surfaces. The distal end is condylarly divided. Behind, the condyles are separated 
by a wide shallow groove which ascends some distance on the shaft. The length of 
the humerus figured in Plate 79, fig. 1, is 13*6 centims. 
Ulna (Plate 79, fig. 3).—Its proximal end is larger than that of the radius and it 
seems to have well-formed olecranon. The shaft and the distal end are slender. Its 
length slightly exceeds that of the radius. 
Radius (Plate 79, fig. 3).—The length of this bone is about 12*5 centims. in a 
skeleton in which the humerus is about 13*6 centims. long. The breadth of its carpal 
end is 21 millims. The expanded carpal end is the chief support of the manus. 
Manus (Plate 79, fig. 3).—A proximal row of carpalia appears to consist of a large 
os radiate and a smaller ulnare. The metacarpals are much smaller than the meta¬ 
tarsals. The ungual phalanges resemble in form those of the pes, but are smaller than 
these. 
In its extreme simplicity the shoulder girdle of Hypsilophodon differs from that of 
most extinct Lizards. Its coracoid , in respect of its simple crescentic form, devoid of 
bony procoracoid, agrees with that of every other dinosaur yet known. It is imitated 
in Hatteria and in Chameleo , and is very unlike the long, narrower coracoid of Cro- 
codilians. The sternum, in respect of its shape, resembles the (cartilaginous) sternum 
of Crocodiles more than that of Lizards, except Chameleo. The scapula, as regards its 
length and narrowness, closely agrees with that of Iguandon Mantelli, I. Prest- 
wichii, and Megalosaurus , and differs from that of Hylceosaurus , of Scelidosaurus , of 
Crocodilia and extant Lizards except Chameleo . The humerus in the greater ex¬ 
pansion of its ends and the slenderness of its shafts resembles that of a Lizard more 
than that of a Crocodile. The inner tuberosity of the proximal end resembles that in 
* See postscript. 
6 S 2 
