1870. ] DR. J. MURIE ON SAIGA TARTARICA. 455 
four. The hindermost pair of processes are the most delicate of all. 
Metapophysial prominences of moderate elevation rise up from the 
root of each transverse process, and they barely pass forwards beyond 
the zygapophysial articulation. The spines, nearly uniform in height, 
decrease in breadth from the lst to the 7th, the last being less than 
half the breadth of the first. 
Though the neurapophyses are pretty vertical, they appear to 
slant forwards from their anterior extremities being elongated as a 
blunt spine. The body of the hindermost lumbar vertebra is the 
stoutest and shortest, those in front subequal in long diameter. 

Side view of sacrum, caudal vertebra, and pelvis of male Saiga: 3 nat. size. 
L.6 & 5. The sixth and fifth lumbar vertebrx, the pointers being directed to 
their spines. S. Sacrum. C. 1. First caudal vertebra. a.s.sp. Anterior 
superior spine of the ilium. c.¢. Crest of the ilium. 7. sp. Ischial spine. 
t.z. Tuber ischii. ¢.sp. External spinous process of ischium. p. sp. Pubic 
spine. 
The four coalesced sacral vertebrae together present the crucial 
figure which usually obtains in Ruminants. The first of the four 
vertebral elements, or that which yields the main abutment to the 
ilia, is a trifle over $ of an inch lengthwise in body ; but transversely 
the diameter from the margin of one sacro-iliac synchrondrosis to 
the other is three inches. The pelvic surface is very level and 
smooth, and the auricular portion or augmented transverse process 
of moderate dimensions. The second, originally separate, element of 
the sacrum, here only distinguishable by the presence of the fora- 
mina, appears to have a limited share as a buttress against the ilium, 
just anterior to the bay of the great sciatic notch. It, along with 
the third and fourth segments of ossification, compose the narrow 
distal or handle end of the cross-shaped sacrum. The transverse 
processes and metapophyses are cemented together, so as to represent 
a doubly shelving mass on either side of the bodies. The four neural 
spines constitute but one consolidated mass, a couple of inches long, 
and dorsally thickened. ; 
