1870.] DR. J. MUKIE ON SAIGA TARTARICA. 465 
and only narrows towards the rostral insertion of the vomer, where 
it is convexly ridged. The long lamellar external and internal 
pterygoid plates are so closely conjoined as to be with difficulty 
recognized as separate elements. The former, lanceolate, and 3 inch 
in greatest breadth, springing in front of the sphenoidal foramen, 
does not, as in Capra and Ovis, trend so horizontally forwards, 
but strikes more obliquely down, and suturally connects itself with 
the vertical palatine plate. Its posterior edge agrees with the Ante- 
lope’s in being narrow, and not everted, as in Sheep and Goats. The 
latter, internal spheno-pterygoid plate is even more delicate at its root, 
and arises close to the posterior edge of the pterygo-palatine plate, 
thence running backwards at a sharp angle to the external pterygoid 
plate, lays like a splint inside it, and again curves forwards, to be 
prolonged into a thicker but nevertheless slender rod, terminating 
in a short hamular process. The alisphenoids, as in Ovis, present 
only a rudiment of that bony plate so conspicuously developed 
forwards at the back of the orbit in Pantholops and other of the 
Antelopes. The sphenoidal wing in Saiga is altogether small, ob- 
liquely ridged, contracted antero-posteriorly, and curved sharply 
backwards between the postfrontal and squamo-temporal elements. 
The orbito-sphenoid seen from below has a larger superficies than 
the alisphenoid, though in itself small. It has a smooth concave 
surface, the foramen opticum obliquely penetrating it just above the 
root of the internal spheno-pterygoid plate. 
(C) The Mandible.—The dentary portion of the body of the 
bone, when the mandible is placed in natural position, has a moderate — 
curvilinear direction upwards and forwards. At the last molar its 
vertical depth is 14 inch, but, correspondingly, less than | inch at the 
premolar. Anteriorly the diasteme narrows very considerably in a 
tapering manner, and then widens into a somewhat scooped or shovel- 
shaped symphysial part, 1 inch long and as much wide, into which 
the horizontally placed incisors are inserted. A diminutive ridge 
runs backwards from each outer incisor towards the molar alveolus. 
The mental foramen is situated, outside, immediately behind the 
symphysis. The ascending ramus, as mentioned, strikes upwards 
at nearly right angles to the dental plane, the angle being produced 
as a thin but broad and rounded sweep of bone. The head of the 
condyle is short-necked, the articular surface transversely oblong and 
very gently concave. The sigmoid notch is shallow and narrow, the 
long coronoid process of nearly uniform breadth throughout. 
The inferior maxilla in the male measured 73 inches horizontally 
from symphysial extremity to ramal angle; and adding an inch for 
the niedian incisors, the extreme length would be 8 inches. 
(D) Dentition.—In the Society’s adult male specimen the set of 
teeth were deficient in the anterior lower premolar and two middle 
incisors. I found the skeleton at the College of Surgeons more com- 
plete, and answering to Pallas’s brief statement of the dental numbers 
in the full-grown animal. The formula, therefore, of the permanent 
dentition is that of other hollow-horned Ruminants, to wit :— 
pe oy 3-3 3-3 
