1865.] AXIAL SKELETON IN THE PRIMATES. 551 
tion ; but in Man it appears constantly to bifureate ; it does so also 
almost constantly in the Nycticebine, often in Hapale, and some- 
times in Simia, Colobus, and Cynocephalus. 
In Lemur, the transverse process being developed concomitantly 
with the antero-posteriorly extended neurapophyses, the vertebral 
artery may be said rather to traverse a bony canal than merely to pass 
through a foramen. This condition is still more marked in Indris. 
The lowest part of the neurapophysis is, on each side, produced 
so as to embrace the posterior part of the body of the axis. In all 
the Anthropoidea, in Lemur, and in the Nycticebine these produced 
parts extend about as far forwards as do the anterior zygapophyses, 
sometimes a little beyond them (e. g. Chimpanzee, Orang, and Ateles), 
sometimes not quite so far forwards (e. g. Lemur); but in Indris 
we for the first time meet with anterior zygapophyses which extend 
much more forwards than do the roots of the neurapophyses. 
The fourth Cervical Vertebra.—In none but Man, and not con- 
stantly in him, has this vertebra a decidedly bifurcated spinous pro- 
cess, though a trace of bifurcation is sometimes found in that of the 
Chimpanzee. In the Gorilla this process is exceedingly produced, 
being the absolutely longest neural spine attached to any vertebra 
of that or of any other species of the whole order. 
In Simia, Perodicticus, and Arctocebus it is also very much pro- 
longed. In Hylobates and all the lower Simiide it is shorter than 
that of the axis. In some of the Cebide, especially Ateles (fig. 6) 
and Chrysothriz, it is, like the spine of the third cervical vertebra, 
somewhat curved forwards. 
In Mycetes (fig. 1) it is rather longer than in the other Cedide, 
and still shows an indication of that trifid character presented by the 
axis and third cervical vertebre. 
In the Lemuroidea, except Perodicticus and Arctocebus, it is, as 
already mentioned, short, and in Loris, Tarsius, Galago, and Chei- 
romys almost or quite obsolete. 
The transverse process is always bifurcated at its extremity, except 
in Lemur and Indris. Even in Lemur there is a slight incipient bi- 
furcation ; but this is never the case in Indris. 
The fifth Cervical Vertebra.—In Man alone is the spinous process 
of this vertebra ever distinctly bifurcated. 
In none but Indris is its transverse process constantly without 
even a trace of bifurcation. 
On the whole, this vertebra repeats the characters of the fourth 
cervical. Its spine* is generally as long as, or rather longer, rarely 
(e. g. sometimes in the Gorilla and Orang) it is somewhat shorter, 
than that of the fourth vertebra. 
The transverse process has its upper and lower extremities rather 
more produced and separated than in the preceding vertebra, the bi- 
fureation becoming thus deeper and more marked. 
Occasionally in A¢eles (fig. 6) and Mycetes the upper portion of 
* In the skeleton of a young Chimpanzee in the British Museum (marked 
27) the spinous processes of this and the following vertebra are quite anchylosed 
together, the neural laminz remaining distinct. 
