1865.] AXIAL SKELETON IN THE PRIMATES, 573 
cervical vertebra, appearing as an obtuse prominence developed from 
beneath the anterior zygapophysis. 
In both Perodicticus and Arctocebus it is also plainly to be recog- 
nized in the corresponding vertebre, and is similar in form and posi- 
tion to the cervical metapophysis of A¢eles. 
That this prominence is really metapophysial in its nature is made 
evident by the fact that in the Edentata, where these as well as the 
other vertebral processes are carried to their maximum of develop- 
ment, the metapophyses are continued into the cervical region in the 
very same situation (viz. dipping beneath the anterior zygapophyses), 
as may be well seen in the two-toed Sloth (in spite of the poor deve- 
lopment of the metapophyses in its trunk vertebree*), also in Orycte- 
ropust, and especially in the Pangolint. The existence of similar 
tubercles in the cervical vertebrae of Myrmecophaga tamandua and 
Myrmecophaga jubata has already been recorded by Professor Owen, 
who has fully recognized their metapophysial nature§. In this last- 
mentioned genus the metapophyses are very marked in the cervical 
region, and are developed with a singular uniformity from the ante- 
rior cervical to the posterior caudal vertebre. 
In the other genera of Primates|| this process is not so distinctly 
to be traced in the cervical vertebree ; yet often the under surface of 
the anterior zygapophyses of the fourth, fifth, or sixth cervical ver- 
tebrz is strongly convex, as is, at least sometimes, the case in the 
genus Homo]; and doubtless this prominence in all cases is, so to 
speak, a latent metapophysis. 
In the Orang ** I have noticed a condition which is common enough 
in many genera of Mammals, namely, such an extension of the cervical 
metapophysis, that part of it is continued on to the posterior part of 
the vertebra next in front, part of a cervical metapophysis occupy- 
ing its normal position beneath the anterior zy gapophysis of one ver- 
tebra, the other part being situated outside and partly upon the 
posterior zygapophysis of the vertebra anterior to it. Ihave not ob- 
served this in any other Primate besides the Orang, except Man, in 
whom, at least sometimes ++, a more or less similar condition obtains. 
* Noticed by Prof. Owen, ‘ Memoir on the Megatherium,’ p. 740. 
t See detached cervical vertebra: (no. 2339) in the Museum of the Royal Col- 
lege of Surgeons. 
{ No. 2363. in the Museum of the Royal College of Surgeons. 
§ Memoir on the Megatherium, pp. 745, 746. 
|| In the British Museum there is a skeleton of an Orang (nos. 43, 10, 2, 1) 
in which the seventh cervical vertebra shows distinctly the metapophysis closo 
to and just outside of the anterior zygapophysis, ready to dip beneath it in the 
sixth, Also, in a skeleton of Cercopithecus albogularis (no. 17 6), the metapo- 
physes are distinctly visible throughout the dorsal vertebrze, those of the first 
two dorsal being more internally situated than are those behind, so that the 
margin of the anterior zygapophysis of the first dorsal vertebra seems quite in 
series with them. The same approach of the metapophyses to the anterior zy- 
gapophyses takes place in a very marked way in the first dorsal vertebra of a 
skeleton of Mycetes (no. 44 a), and in that of Ateles subpentadactylus (no. 38 b). 
{ Well seen in the fourth, fifth, and sixth cervical verlebree of a human spine 
in the Museum of St. Mary’s Hospital. . 
** See skeleton (nos. 45, 10, 2, 2, 3c) in the British Museum. 
tt £. 9. a set of human cervical vertebrae in my own collection. 
