4 
636 GEOLOGICAL SURVEY OF THE TERRITORIES. 
the canal is open laterally in this segment. It is confined to the anterior 
third on each side of the vertebree enumerated, and is exceedingly smal! 
throughout its extent; its largest calibre being at its commencement, 
its finest in the tenth or eleventh. Among the long vertebre in the 
middle of the neck the anterior entrances of the vertebral canal are 
ellipses placed vertically. They become more circular as we approach 
the theracic end of the chain. On the eighth vertebra, mesially, and 
beneath anteriorly, we find, bounded on either side by the parapophysial 
processes, the commencement of the interhyapophysial groove or canal 
tor the carotid artery. It extends through the fourth vertebra with 
about an equal amount of distinctness and depth. 
A neural spine is feebly developed upon the axis posteriorly, this 
process becoming more strongly marked on the summits of the next 
three succeeding vertebra, the remainder of the cervical segments being 
devoid of this feature, though we have occasionally found an evident 
attempt at its reproduction in the ultimate cervical. The nethermost 
portion of the pseudo-centrum of the first vertebra has been considered 
to be the atlantal hypapophysis. Be this as it may, the hypapophysis 
of the axis certainly has a much greater claim to be termed a process, 
while on the third and fourth segments this spine constitutes one of 
the most marked features of the vertebra, being a longitudinal and quad- 
rate lamina of bone, equally well developed on the two vertebra in ques- 
tion, directed immediately forward. In the case of the fifth cervical the 
hypapophysis has again degenerated to a minute median point, to be 
entirely obliterated in the sixth. At the ninth it again makes its ap- 
pearance as a delicate and flattened plate at the anterior margin of 
the vertebra beneath, at the point at which in the carotid canal itis first 
seen in the eighth. In the remaining ones it is prominently developed 
and directed forwards from the median plane in each vertebra as a quad- 
rate lamina. It is usually triplicate in the last, but does not arise from 
a common stem, as in other birds. 
Parapophysial processes appear as lateral spines first on the third 
cervical; in the middle of the series they are very long and delicate, 
being parallel with the centrum of the vertebra to which they belong. 
They become markedly suppressed near the termination of this division 
of the spinal column. 
Anterior and posterior zygapophyses retain throughout the cervical 
vertebre their most common ornithic features; in the middle of the 
neck the postzygapophysial processes are long and bent slightly towards 
the neural canal, leaving quite an extensive lozenge-shaped space be- 
tween them in this region where the chord is unprotected by bone; the 
interarticular facets among the centra likewise retain their most com- 
mon avian characteristics. The bodies for the most part seem to be 
slightly compressed from side to side, with a faint inferior median crest. 
The fourth vertebra has a delicate and outwardly-arched interzy gapo- 
physial bar, that includes within it an elliptical foramen on each side — 
of some size. This bony connection in the third vertebra nearly fills in 
the interzygapophysial space, a very minute vacuity alone remaining. 
_ All the cervical vertebrae appear to be pneumatic, but the foramina 
in some of them are excessively small and difficult of detection. 
The bony cup of the atlas is not usually pierced by the odontoid 
process of the axis, but one cannot but wonder, this cup being less 
than half a millimetre across, that the skull, so very large as compared 
‘with its tiny occipital condyle, should not be subject to frequent dis- 
locations; this undoubtedly would be the case were not the occipito- 
