552 MR. ST. GEORGE MIVART ON THE [June 27, 
the bifurcated transverse process itself more or less bifureates, deve- 
loping a small backwardly projecting secondary process, which is 
perhaps a nascent anapophysis. 
The sixth Cervical Vertebra.—This very characteristic vertebra is 
in none but Man ever provided with a bifurcated spinous process, 
and it is often simple in him. It is very long in J’roglodytes and 
Simia, also in Perodicticus and Arctocebus. In Tarsius it is rudi- 
mentary, and in Galago (fig. 8) and Cheiromys obsolete. In the 
other forms it is moderate, sometimes exceeding and sometimes fall- 
ing short of the length of the spine of the axis. 
The transverse process is subject to much individual variation as 
to the extent of development and the form of its pleurapophysial 
portion. It is mostly more extended than in Man, either trans- 
versely or antero-posteriorly, or both. Thus even in the Gorilla it 
is rather more antero-posteriorly, and much more transversely, pro-> 
duced than in him ; it also diverges much more from the upper part 
(diapophysis of Professor Owen) ; but in the adult Chimpanzee it is 
very human in its proportions. In none above Hylobates does the 
antero-posterior extent of the costal element equal the antero-poste- 
rior length of the under surface of the centrum. In the Simiide, 
other than the Simiine, however, this element generally becomes 
much antero-posteriorly extended, exceeding the centrum in length. 
But sometimes it is only its outer border which is so expanded, the 
hinder margin being more or less deeply excavated, so that the costal 
parts take the form of two long processes, one springing from beneath 
each vertebral foramen, and the two running back parallel to each 
other, beneath the transverse processes of the seventh cervical ver- 
tebra. Amongst the Cebide there is considerable variation. Some- 
times in Afeles (fig. 6), as also in Nyctipithecus and Pithecia, the 
costal part of this vertebra is scarcely larger than the corresponding 
part of the fifth vertebra; and the same is the case in Loris, Pero- 
dicticus, and Arctocebus. In Lemur, on the other hand, it is large, 
and exceeds the centrum in length. 
In Aéeles (fig. 6) and Mycetes the upper part of the transverse pro- 
cess, or diapophysis of Owen, often presents a distinct anapophysis. 
In Indris the diapophysial process, which projects from above quite 
the anterior end of the costal element, so much resembles the entire 
transverse process of the more anterior vertebree that the pleurapo- 
physial part seems, in this genus, to make its appearance for the first 
time in this sixth vertebra. It depends from the outer side of the back 
part of the under surface of the centrum, and is very conspicuous. 
In the Orang the transverse process is sometimes only grooved, 
instead of being perforated, by the vertebral artery. 
The seventh Cervical Vertebra.—The neural spine of this vertebra 
never bifurcates. Except in the Gorilla, the Orang, and the Aye- 
Aye, it is the longest, or equal to the longest, of the cervical spines 
posterior to the axis. It generally exceeds, but sometimes falls short 
of, the spine of the axis in length. In Perodicticus and Arctocebus 
it very considerably exceeds it; but in Tarsius, Galago, and Ohei- 
romys it very greatly falls short of it, in the last-named the spine 
