1870. ] MYOLOGY OF CHAMALEON PARSONII. 871 
The flexor profundus digitorum (figs. 10, 14, 15, 16, & 28, F. D) 
takes origin by only two heads. The first of these arises from the 
internal condyle in union with the similarly arising head of the flexor 
longus pollicis, and similarly embraced by the tendons of origin of 
the flexor carpi radialis. The second head springs from the 
radial side of the olecranon, and from the radial aspect of the 
ulna for about its upper three-fourths, its summit being con- 
tiguous (fig. 16) to the ulnar side of the insertion of the brachialis 
anticus.. The two parts of the muscle having united about the 
middle of the forearm, it extends distad, and ends ina strong tendon 
which passes in a deep groove at the distal end of the ulna, and side 
by side with the tendon of the flexor longus pollicis. The tendon 
then bifurcates. The radial bifurcation very soon receives a short 
slip from the ulnar bifurcation, then a long slip from the flexor 
longus pollicis (its fourth and most ulnad tendon), and finally a long 
and very delicate slip, one more from the ulnar bifurcation. It then 
goes to the fourth digit. The ulnar bifurcation gives first a very 
short, and then a long and very delicate slip to the radial bifurcation, 
and then goes to the fifth digit. 

Deepest flexor surface of right forearm. 
B. Biceps. F.D. Flexor profundus digitorum. PP. A. Pronator accessorius. 
P.Q. Pronator quadratus. P.T. Pronator teres. S.Z, Supinator longus. 
Lumbricales (fig. 28). There are three lumbrical muscles in the 
hand. 
The first of these arises from the ulnar side of the long flexor 
tendon of the fourth digit, and goes to the same side of the same digit. 
The second arises from the radial side of the long flexor of the 
fourth digit, and goes to the same side of the same (fourth) digit. 
The third arises from the ulnar side of the long flexor tendon of 
the third digit, and goes to the same (ulnar) side of the same (third) 
digit. 
Foor brevis digitorum. This muscle is confined entirely to the 
hand. It springs from the annular ligament which passes from the 
first to the fifth metacarpal, and is inserted into the digits, the long 
flexor tendons passing between its fibres. 
Flexor brevis pollicis (fig. 8, B.P). A thick, short muscle 
which may perhaps be thus named arises from the palmar ossicle 
and annular ligament, and is inserted into the radial margin of the 
Proc. Zoou. Soc.—1870, No. LVIII. 
