868 MR. ST. GEORGE MIVART ON THE [ Dec. 6, 
The brachialis anticus (figs. 1, 13, 16, B.A) occupies the whole 
antero-external aspect of the humerus, extending upward as far as 
the insertion of the deltoid. On its outer side it has the external 
head of the triceps; and on its inner side it has the biceps, the short 
part of the coraco-brachialis, and the insertion of the pectoralis. 
Passing downward (and much uniting on its ulnar side with the 
biceps, which wraps it round anteriorly) it is inserted into the flexor 
surface of the ulna, just below its articular surface for the humerus, 
and between the tendons of insertion of the biceps. Its insertion 
is conterminous (fig. 16) with the upper part of the ulnar origin of 
the flexor longus digitorum. 
Supinator longus * (figs. 1,9, 11,&15,8.LZ). This muscle is 
very large, but not so distinctly double as in the Iguana. Its more 
superficial portion arises from the external condyle, and is inserted 
into the outer side of the radius for almost its whole length. Its 
deeper portion springs from quite the lower end of the humerus, ex- 
ternal to its articulation with the radius. It is inserted into the upper 
half of the extensor surface of the radius. 
The superficial part is closely connected, toward and at its origin, 
with the extensor carpi radialis longior, but is separated from it dis- 
tally by the extensor ossis metacarpi pollicis. Ulnad it is con- 
terminous with the insertion of the pronator teres. The deeper part 
is not only intimately united with the extensor carpi radialis longior, 
which covers it, but also with the long part of the extensor ossis me- 
tacarpi pollicis. 




Outer surface of right scapula and upper arm. 
B. Biceps. B.A. Brachialis anticus. D! & D®. Deltoid. LZ. Levator clavi- 
cule. O.H. Omo-hyoid. P. Pectoralis. S! & S?. Suprascapuiars. 8. C. 
Subelavius. S. W/. Serratus magnus. 7. & T*. Triceps. Zr. Trapezius. 
Extensor carpi radialis longior t (figs. 1, 9, & 11, H.R. L). This 
muscle arises by tendinous fibres from the outer surface of the exter- 
nal condyle superficially to the long portion of the supinator longus, 
* Meckel, /. c. p. 367. t Meckel, 7. c. p. 381. 
