to 
ON RHAMPHORHYNCHUS BUCKLANDI 
but its edges are broken and rounded off, and it was probably much 
wider and abruptly terminated at the end. 
The upper (or posterior) surface is a little concave from side to 
side ; the lower (or anterior), convex. The inner edge is thick and 
rounded; the outer, thinner. The anterior portion of the coracoid 
is wider below than above, its anterior inferior edge being produced 
outwards into an elongated tuberosity, which causes the outer face 
of this part of the bone to appear concave from above downwards, 
and the more so as the anterior upper part of the bone is equally 
produced to form the lower boundary of the glenoid cavity for the 
humerus. The anterior and inner part of the coracoid is elongated 
into a short process, whose extremity is broken off. 
The anterior extremity of the coracoid bends up at right angles 
to the rest of the bone, to form a very stout bony mass, gths of an 
inch thick, which passes without a trace of suture into the scapula. 
This perpendicular scapulo-coracoid portion of the bone measures 
12 inch from the lower edge of the coracoid, is half an inch thick 
from side to side, and about the same antero-posteriorly. The 
glenoid cavity is situated on the anterior half of its outer face, is 
concave from above downwards, and would appear to be much more 
so if its projecting upper and lower boundaries were not broken 
off; it is convex from side to side; and if the coracoid be held 
horizontally and with its long axis directed antero-posteriorly, it 
looks forwards and outwards, while its axis is directed downwards, 
forwards, and inwards. Only avery small fragment of the scapula 
remains above the glenoid cavity; it does not present a sufficiently 
determinate form to be worth description. 
I should not have felt so confident in my determination of the 
nature of this part, had it not been for the clear manner in which 
the structure of the coraco-scapular arch is to be seen in the original 
specimen of Dimorphodon macronyx, to which I have already referred. 
As Dr. Buckland’s description of these parts is very brief and 
as, with the aid and permission of my friend Mr. Waterhouse, I was 
able to relieve them more extensively, and thereby develop some 
important and hitherto unnoticed peculiarities of structure, it may be 
useful if I describe the left coraco-scapular apparatus in D. macronya, 
which is now very perfectly displayed in the original specimen in 
the British Museum (P]. XXIV [Plate 10] fig. 6). 
The coracoid bone is 1} inch long. Its anterior end is thick and 
strong, and compressed from side to side. Below the glenoid cavity, 
its outer face is nearly plane from before backwards, but is concave 
! Geol. Trans. 2nd ser. vol. iii. p. 221. 
