1870. ] DR. J. MURIE ON SAIGA TARTARICA. 453 
vertebral foramina pierce the sides of the body almost vertically, 
close behind the root of the cranial articulating processes. The 
postarticular surface of the body is tolerably level and semilunar. 
A short knobby sessile projection represents the ventral keel (hypa- 
pophysis); it is situated far back. 
As regards the antero-posterior diameters of the bodies of the 
cervicals, the following numbers express a sufficiently near approxima- 
tion to their relative sizes in inches and decimals :—Ist, 1°2; 2nd, 
2:3; 3rd, 1:6; 4th, 1°6; 5th, 1°5; 6th, 1:3; 7th, 1:0. 
By such it is seen that the axis is the longest of the neck-vertebre, 
as, indeed, obtains in many of the Ruminantia, although in the long- 
necked Giraffe and Camelidz, where the whole of the cervicals are 
subequally long, it is not so obvious. Its neural spine is also by 
far the strongest, an inch high, and two antero-posteriorly ; thick 
and stout, with an expanded, roughened, free border, cleft behind 
(hyperapophyses of Mivart*), but single and produced in front, 
where it overlies the posterior incised portion of the laminar arch 
of the atlas. The wide foramen for the vertebral artery enters the 
spinal canal at the anterior end and upper lateral surface of the 
body. The odontoid process is short, gouge-shaped, and surrounded 
by a wide, flattened, semilunar articular surface. The transverse 
processes are of considerable size, though nevertheless small, as com- 
pared with the great wing-like processes of the atlas. Moreover 
they disagree with these latter in being concave below and more 
convex above, and in their derivative angle from the body being 
more acutely backwards. There is only a rudiment of a pleurapo- 
physis at the root of the diapophysis. A deepish ventral spine exists 
for nearly the whole length of the body. Posteriorly it is bulbous, 
but in front of this thin, sharp, and laterally compressed. 
The third and fourth vertebrze present characters very much akin 
to each other. They agree in the great reduction of the spine, 
deeply bifid in both, smallest in the third, but in each only occu- 
pying the anterior half of the neural arch-—in the great lateral ex- 
pansion, flattening, or even forward concavity of the neural laminee— 
in the broadening and more outstanding position of the transverse 
processes—in possessing large diapophyses—in the production of 
the keel being slightly less than in the axis, and more concavely 
marginate. 
The distinctive differences are:—in the fourth having the highest 
spine; but the third, while less high, has the neural lamine pro- 
duced forwards as a low process, which fits into the triangular in- 
terspace between the posterior articulating (or zygapophysial) facets 
of the axis; in the laminar arch of the third being slightly broader 
and less concavely marginal; in there being only an obscure metapo- 
physis in the third, whereas it is fairly developed in the fourth ; in the 
transverse process and diapophysis of the third running antero-pos- 
teriorly almost in the same plane, whilst in the fourth they are at 
a distinctly obtuse angle to each other. 
The alteration of the configuration of the fifth cervical consists in 
* ‘Axial Skeleton in the Primates,” P. Z. S. 1865, p. 576. 
