(54 GEOLOGICAL SURVEY OF THE TERRITORIES. 
Of the vertebral column.—The manner in which the vertebral column 
of birds should be divided has been differently viewed by ornithotomists. 
The two principal reasons for this difference of opinion, no doubt, has 
arisen from the various arrangements assumed by the free ribs at the 
anterior part of the column, and the equally diverse manners in which 
the innominate bones of the pelvis attach themselves to the column. 
Without entering very extensively into the literature of the subject, let 
us first examine into the question as to where the line shall be drawn 
between the cervical and dorsal vertebrze. Weseem to have presented 
us here two very uncertain guides; the first being whether the first 
free ribs are connected with the sternum by sternal ribs or hemapo- 
physes, and the second upon the character of the vertebre—that is, 
whether they have the appearance of dorsals, as we usually find them, or 
cervicals as we usually recognize them. Professor Huxley sharply de- 
fines the line when he says: ‘The first dorsal vertebra is defined as 
such by the union of its ribs with the sternum by means of a sternal rib; 
which not only, as in the Crocodilia, becomes articulated with the ver- 
tebral rib, but is converted into complete bone, and is connected by a true © 
articulation with the margin of the sternum.” (Anat. Vert. An., p. 237.) 
Professor Owen takes a different view of the subject when he states that 
‘In the first and second dorsals the pleurapophysis (1 and 2) terminate 
in a free pointed end, like the ‘false floating ribs” of Anthropotomy; 
in the third the pleurapophysis, pl. 3, articulates with the hemapophy- 
sis h; which, in connection with its homotypes, constitutes the bone 
called ‘sternum,’ f.” (The letters given refer to a cut showing the first 
three dorsal vertrbre and scapular arch of a bird, in diagrammatie side 
view. ‘(Anat.of Verts., Vol. LI, p.15.) It willbe remembered that when 
we examined into the osteology of Hremophila we found sometimes that 
the second pair of free ribs, or rather freely articulated ribs, were con- 
nected with the sternum by hemapophyses, so that in this case some 
would claim them as true dorsals, or as dorsals any way (Owen); while 
others could but say that the number of pairs of dorsal ribs varied. 
This state of affairs in Hremophila is no more-an impossible thing or un- 
usual occurrence than the occasional presence of cervical ribs in man. 
(Owen, Anat. Verts., Vol. II, p. 298.) 
Now, among the Tetraonide we found another condition that proved 
equally puzzling; with them it will be recollected that there were, in 
the backbone in the dorsal region, four vertebree that in the adult were 
completely fused together, and that the pairs of ribs that articulated 
with the anterior vertebra of this compound bone did not connect with 
the sternum by hemapophyses. Here we must, if we consider the float- 
ing ribs in this region as cervical ribs, consider that a cervical vertebra 
has become anchylosed with three dorsals, together forming a bone that 
we believe every one would, as the writer then did, say was composed of 
dorsal vertebre alone, in spite of the anterior ribs not joining the 
sternum by sternal ribs. One other case, and let us take a specimen of 
Asio wilsonianus to illustrate it. In this bird we discover, passing from 
before backwards, that the first pair of free ribs hang from beneath the 
transverse processes of the vertebra as diminutive bonelets, as we found 
them in Speotyto. Now, the next vertebra behind this one has all the ap- 
pearances of a true dorsal vertebra, (possessing the lofty neural spine, 
ete.); but the ribs still fail to connect with the sternum by sternal ribs. 
These three varieties may be again divided when we come to consider 
the appearance or non-appearance of uncinate processes upon these 
ribs, a condition which likewise varies. At present Ido not propose to 
definitely state my views in regard to this matter, but it will be seen | 
