388 MR. ST. G. MIVART ON THE ANATOMY OF ECHIDNA HYSTRIX. 
immediately on the outer (radial) side of the insertions of the supinator longus and pro- 
nator teres. The posterior interosseous nerve is not given off from the radial, as in man, 
but is distinet at the back of the elbow; it traverses the ériceps, and, passing over the 
external condyle (external to the radial nerve), it perforates the supinator brevis. 
Anconeus.— This muscle is rather largely developed. It arises from the outer and 
posterior surface of the external condyle, and is inserted into the depression beneath the 
sigmoid cavity, on the radial surface of the ulna and olecranon. 
The pronator teres (Plate LIT. fig. 2, P.T) is a long and very strong muscle, arising from 
the internal condyle and the septum between it and the flexor carpi radialis, and being 
inserted intot he radial margin and anterior surface of the radius, from the lower end of 
the insertion of the diceps, almost down to the wrist. 
The flexor carpi radialis (Plate LII. figs. 2 & 3, F.R) arises by’a strong tendon from the 
internal condyle, also, by another tendon, from a depression on the ulnar side of the distal 
articular surface of the humerus, and, besides, by muscular fibre from the anterior surface 
of the lower border of the internal condyle. The fibres from these origins converge 
to a very strong tendon, which is inserted into the metacarpal bones both of the pollex 
and index. 
The palmaris longus is fused with the enormous flexor digitorum. 
There is no trace of a pronator quadratus. 
Flexor carpi ulnaris (Plate LII. figs. 1, 2 & 3, r.v.).—This is an enormously wide sheet 
of muscle, which arises from the inner (ulnar) border of the olecranon and ulna down to 
the wrist, and also from the inner part of the lower border of theinternalcondyle. Pass 
ing downwards, its tendinous surface receives the tendon of the first portion of the 
latissimus dorsi; and the two muscles becoming thus intimately united, are together 
inserted into the pisiform bone. 
There is a muscular fasciculus (more or less distinct from the superior border of the 
flexor carpi ulnaris) which arises by strong tendinous fibres from the radial aspect of the 
extremity of the olecranon, and is inserted into the internal condyle immediately below 
the common insertion of the second portion of the latissimus dorsi and the dorso-epi- 
trochlear. At its origin it is very closely connected with the adjacent fibres of insertion 
of the humeral part of the triceps on one side, and the fibres of origin of the flexor carpi 
ulnaris on the other. Of course it arches over the ulnar nerve. 
Flexor communis digitorum (Plate LII. fig. 3, r.c).—There is a single, but enormous, 
muscular mass which appears to represent the palmaris longus, the flexor sublimis, the 
flexor profundus, and flexor longus pollicis all fused together. It arises from the whole 
length of the ulna, from the olecranon down to the wrist, and from the whole length of the 
inferior margin of the internal condyle, and forms (when the forearm is horizontal and the 
palm upwards) a vertically extended sheet of muscle, the narrow edge of which is visible 
on the surface. A small superficial portion, which arises from the extremity of the internal 
condyle and which is more or less separable from the rest, may perhaps represent t : 
palmaris longus. The largest portion, which arises from the whole length of the inte 
condyle, appears to represent the flexor sublimis, as it is the part below, which is suf 
plied by the anterior interosseous nerve (given off from the median, as usual), and whi 
dm nn ln heul SU ee ee 
