The Muscles 107 
surface of the humerus, just distal to the lateral 
process; while its superficial layer, especially the 
upper fibers, come directly from the deltoides 
scapularis inferior and therefore have their origin 
on the scapula. In the middle of the upper arm 
it becomes a slender round tendon that extends, 
through a tendinous loop, to the radius, on whose 
outer side, at the end of the proximal third, it is 
inserted. 
MUSCLES OF THE FOREARM 
Humero-radialis Internus (Radialis internus, 
Lange Vorwartswender, Pronateur, Pronator teres, 
Pronator quadratus, Oberflachlich gelegener, lan- 
ger runder Einwartsdreher). This muscle arises 
from the condylus internus (C. ulnaris s. medialis) 
and attaches itself to the radius throughout almost 
its entire length. It is a fairly strong muscle. 
Ulno-radialis (Carré pronateur, Pronator teres, 
Pronator quadratus, Muskel welcher dem Prona- 
tor quadratus entsprect). A strongly developed 
muscle. It springs from the upper part of the 
flexor surface of the ulna and is inserted on the 
lower part of the flexor surface of the radius. 
Humero-radialis Longus (Plate II., Figs. 1 and 
2,1) (Supinator longus, Long supinateur, Lange 
Ruckwartswender, Supinator radii longus). Among 
the Crocodilia this and the following muscle are 
well developed. This one springs from the con- 
