1870. ] MYOLOGY OF CHAMZLEON PARSONII. 869 
with which, for some distance, it is very intimately connected. Pass- 
ing distad, and quite separating from the extensor carpi radialis bre- 
vior, it is inserted into the distal part of the dorsum of the third 
metacarpal bone. 
The eatensor carpi radialis brevior (figs. 1 & 11, £. R. B) arises 
from the lower end of the external condyle, and from the humerus, 
quite close to the articular surface for the radius, and outside the 
origin of the deeper part of the supinator longus, with which, for some 
distance, it is intimately connected. Passing distad, and diverging 
from the extensor carpi radialis longior, it passes under a very strong 
‘tendinous arch (which extends from the lower end of the ulna to the 
radius), and is inserted into the ulnar side of the distal part of the 
dorsum of the fourth metacarpal. 
Extensor carpi ulnaris * (figs. 1,10, &11,#.U). This arises by 
a tendon which is common to it and to the larger (or radial) portion 
of the flexor carpi ulnaris. ‘This tendon is attached (beneath the 
tendon of insertion of the triceps) to the back of the humerus, almost 
at its distal extremity. The muscle ends distally ina strong tendon, 
which, dipping down beneath that of the flexor carpi ulnaris, is.in- 
serted into the proximal part of the palmar surface of the fifth meta- 
carpal and of its externally projecting process. 
Pronator teres t (figs. 8, 9, 10, 14, & 15, P. 7’). The round pro- 
nator is very large, and arises by a strong tendon from the internal 
condyle, close to the insertion of the long part of the coraco-bra- 
chialis. It is inserted into about the lower four-fifths of the radius, 
/ toward its outer border. 
The flewor carpi radialis (figs. 8, 9, 10, & 14, F. R) has a double 
origin. One tendon is from the internal condyle immediately below 
the origin of the pronator teres. The other tendon of origin springs 
from near the same spot as the first, but separated from it by the 
summit of part of the flexor profundus digitoram, which is thus em- 
braced between these two tendons. ‘The inner tendon is also much 
connected with the capsule of the joint between the humerus and 
ulna, so that it has the appearance of bifureating. The muscle ends 
below in a strong tendon, which, passing down, with the flexor 
sublimis of the palm superficial to it, is inserted into the proximal 
end of the palmar surface of the first metacarpal, and thence runs on 
to the same part of the fifth metacarpal, thus constituting a palmar 
arch, beneath which the long flexor tendons run. 
Pronator accessorius (figs. 10, 12, 14,15, &16, P. 4). A thick mus- 
cle, which seems to answer to the muscle I have thus named in the 
Iguana{, arises from the internal condyle, immediately beneath and 
within the humeral origin of the flexor profundus digitorum. It also 
arises from the radial border of the ulna and from the interosseous 
ligament, coming into view, when the deepest layer of the extensor 
surface is exposed (fig. 12), above the short pronator quadratus. It 
is inserted into rather more than the lower two-thirds of the flexor 
aspect of the radius (between the insertions of the pronator teres and 
* Meckel, /. c. p. 383. t+ Meckel, /. c. p. 368. 
t See P. Z. 8. 1867, p. 784. 
