SHUFELDT | OSTEOLOGY OF THE TETRAONIDA. 671 
lamella, twisted upon themselves in a manner to conform with the 
superior base of the beak, overlap the frontals, as already defined, are 
separated from each other by the intermaxillary, throwing out below to 
meet this bone a sharp process, thus forming a broad elliptical bound- 
ary limiting the capacious osseous nares. In all adults of this family 
they are easily detached by maceration. These bones are well shown 
in Plate X, Figs. 71 and 73, in the cranium of Cupidonia, from an un- 
usually fine bird sent with a number of others, for which our thanks are 
graciously tendered to Captain Richards Barnett, Medical Department, 
United States Army. It will be observed that the bone becomes so at- 
tenuated in some specimens as to give rise to a foramen, as seen in the 
latter figure. The hemal arch of this vertebra is called the maxillary 
as its lower rib and spine constitute the major share of the superior man- 
dible or maxilla. The pleurapophyses seen in the palatines are long, rib- 
like bones with their anterior ends much flattened from above down- 
wards, to fit into a fissure on either side made for them in the inter- 
maxillary below the maxillaries. Near their middles they curve moder- 
ately outwards to develop compressed heads at their posterior extremi- 
ties, fitting into a notch in either pterygoid, and concave mesially for 
the rostrum of the basi-sphenoid. 
At their inner thirds they send off thin sheets of bone that curve up- 
wards, barely to touch the ramphosial process of the sphenoid, accom- 
panying it as far as it extends distad, then sloping away on the ribs of 
the bones themselves. The hemapophysial maxillaries are elements 
that seldom change their ornithic characters, and in the Tetraonide seem 
to be reduced to their simple typical form—in completing the delicate 
infraorbital bar on the one hand—and just previous to becoming wedged 
into the premaxillary above the palatines, dispatching a bony offshoot 
on either side nearly to meet each other in the palatine fissure on the 
other. 
The remaining pair of bones found at the interior aspect of the bird’s 
skull are the pterygoids. In the Grouse they are stumpy, subcompressed 
concerns, with half-twisted shafts, having broad concave surfaces for 
the facets on the rostrum, which are notched distally for the reception 
of the palatines. The articulation with the tympanies is equally exten- 
sive, monopolizing long, narrow facets beneath the orbital processes on 
those bones. 
We have arrived finally at the point in our descriptive skeletology of 
the avian skull, where we have to deal with the anterior and ultimate 
Gallas baukwa and the Horned Fow] of the Azores. They were presented to the Smith- 
sonian Institution by Mr. Tegetmeier. The vomer is present in neither of these 
crania, although no doubt it may have been originally, and in the drawings made 
from these very crania the vomer has likewise been omitted. (Darwin’s Animals and 
Plants under Domestication. Vol. 1, pp. 275, 279, figs. 34, 36.) 
Other eminent writers describe its development in the following language: ‘‘The 
pre-maxillaries and the rest of the bones of the upper jaw are further advanced in 
development, becoming more solidified, and perfecting the various relations already 
described. A new bone has arisen in the palate, viz, the vomer (v. fig. 65, p. 246), 
which is however but a very small style, lying under the nasal septum, behind the 
points of the maxillo-palatine processes of the maxillaries.” (Parker and Bettany, 
Morph. of the Skull. Section549. Common Fowl, fourth stage.) And again: ‘‘The 
slender maxillary (figs. 64,65) now rises in front into the angle between the descend- 
ing crus of the nasal bone and the hinder edge of the dentary process of the pre- 
maxillary. The maxillo-palatine plates (Mw. p. Fig. 65) are broader and reach nearly 
- to the mid-line, being separated partly by the nasal septum and parely by the small 
vomer, which is rounded in front and split for a short distance behind. The forks of 
the vomer (v.) articulate with the inner and anterior points of the inner plates of the 
palatine bones, which lie side by side mesially, nearly concealing therostrum.” (Ibid. 
. sect. 563. Fifth stage. The chick second day after hatching.) 
