THE GREAT ANTEATER. 133 
The external pterygoideus—a narrower and smaller muscle—is not clearly distinct from 
the foregoing; it arises fleshy from the outer part of the tuberosity of the pterygoid 
bone, and the fibres pass more directly forward to their insertion, where they blend 
with those of the preceding muscle: this external part of the pterygoideus is more 
directly a retractor of the jaw: the other fibres would antagonize the masseteric ones in 
rotatory horizontal movements of the jaw. 
Muscles of the Nose, Ear, and Lips. 
The back part of the upper maxillary bone, which slopes downward and a little 
outward, to form the malar process, affords an aponeurotic origin to four muscles of the 
nose and lips. The levator nasi (Pl. XX XIX. fig. 1, c) is the superior of these; it becomes 
distinct an inch in advance of the common origin, its fleshy fibres converging to a small 
tendon two inches nine lines from that origin: the tendon, which is four inches in length, 
is inserted into the upper part of the nose, which it raises. 
The retractor anguli oris (ib. d) is the second muscle: it comes off from the lower 
and outer part of the preceding, about an inch in advance of their common origin, and 
is aponeurotic on its upper border for two and a half inches. The aponeurosis, which 
forms the tendon of insertion, begins at the lower border of the muscle near where the 
first aponeurosis terminates. The whole length of the fleshy part of this muscle is four 
inches nine lines: its greatest breadth, where distinct, is three lines: the length of the 
slender tendon is two inches; it passes over the orbicularis oris, q, to be inserted into 
the angle of the mouth. 
The retractor ale nasi (ib. e) is the third muscle: it is sent off below and from the 
inner side of the preceding; has a fleshy belly three inches four lines in length, and a 
very slender tendon four inches three lines in length, which passes over the orbicularis 
oris, to be inserted into the skin of the back part of the nostril. 
The retractor labii inferioris (ib. f) is the fourth muscle: it forms the lower and 
outer part of the common origin, covers that of the preceding muscle, has a fleshy por- 
tion five inches six lines in length, and a tendinous one two inches four lines in length. 
This tendon seems to penetrate the orbicularis oris, to the fibres of which it gives 
attachment both along its upper and lower borders. It is inserted into the lip below 
the angle of the small mouth. 
The retractor labii superioris (ib. m) forms a fifth muscle, which has a more distinct 
origin from the malar process of the maxillary, than the preceding four, for the extent 
of one inch. Its fleshy part is three inches three lines in length ; its very slender tendon 
is five inches in length, and is inserted into the upper lip, and to the lower part of the 
nostril, of both of which parts it is a retractor. Near its insertion it is connected with 
muscular fibres descending from the skin of the nose to the circular lip, where ‘they are 
connected with the cutaneous muscles affecting that part. 
The orbicularis oris (ib. q) arises from the outer side near the fore part of the long 
