. Annual report. 1st-12th, 1867-1878. Geology. 688 GEOLOGICAL SUEVEY OF THE TERRITORIES. so open as to give a pretty fair view of the interior of the hone in some cases. The position of the united clavicles, or the free acromial extensions of the scapulae, is shown for Lagopus in my drawing in Fig. 91. Something has been said about this bone already; we will add, however, that the superior ends always terminate by rather tuberous enlargements, smooth internally, but even as applied to the clavicular processes of the coracoids. The shafts are gently curved, of even calibre, and fall nearly dire
. Annual report. 1st-12th, 1867-1878. Geology. 688 GEOLOGICAL SUEVEY OF THE TERRITORIES. so open as to give a pretty fair view of the interior of the hone in some cases. The position of the united clavicles, or the free acromial extensions of the scapulae, is shown for Lagopus in my drawing in Fig. 91. Something has been said about this bone already; we will add, however, that the superior ends always terminate by rather tuberous enlargements, smooth internally, but even as applied to the clavicular processes of the coracoids. The shafts are gently curved, of even calibre, and fall nearly directly downwards in some species, to be slightly expanded beneath in order to give better support for the large median dilatation below; this is triangular in outline, thickened in front, sharpened behind. In Ortyx this process is sometimes produced backwards, so as to nearly touch the sternum; this feature obtains, also, among some of the other Quails. The furculum of Meleagris is very different from that bone, as7 just described in general terms for the Grouse. It is V-shaped, to be sure, but for the size of the bird is extremely slender, the medium plate is smaller than we find it in many of the Quails; the superior halves of the limbs are dilated and exhibit excavations on their inner aspects, at the bases of which we find irregular groups of pneumatic foramen; these limbs terminated above in truncate and thickened ends for artic- ulation with the remaining bones of the shoulder girdle. The furcula of Pavo and Numida are much more like the general type of the bone as found in the Tetraonidce than the same bone in the Wild Turkey is. The bones of the shoulder girdle are all well advanced in ossification in the young chick, : ^ ,\\ but do not develop their distinctive markings until a bird is pretty well along in age; this applies more particularly to muscular lines on the shafts, the base of the coracoids, and the clubbed extrem- ities of the scapulae. In Bonasa, where we noti
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