54 
fleshy and partly tendinous from the entocondyle, and its fibres 
pass distally to be inserted into the shaft of the radius on the 
palmar aspect of its distal fourth. It overlaps the insertion of 
the biceps, and the large median nerve passes under cover of it. 
- The I. pronator quadratus is entirely absent. 
{ am not aware of any other Marsupial in which the pronator quad- 
ratus is absent, and in many it occupies the whole length of the. 
interosseous space,” e.g.,in Wallaby and Perameles. 
The coronoid head of the pronator radii teres is never present in any 
Marsupial, and its general characters in the order are very constant, 
varying chiefly in size and extent of insertion into radius. In some 
cases (Cuscust+) it is inserted into the distal half of the shaft,in others 
(Thylacinus and Dasyvrus+ ) into the middle third or so of the radius, 
and in Macropus{ into the upper third. 
Both in Ornithorhynchus and Echidna the pronator teres is very 
strongly developed, is entocondylar in origin, and is inserted into the 
radial shaft as low as the wrist. 
There is no trace of a pronator quadratus in the J/onotremata. 
Amongst Hdentata the condition of the pronator quadratus is very 
variable. 
In Chlamydophorus$ Macalister found the pronator quadratus repre- 
sented by a fibrous band, whilst Hyrtl found no trace of it. 
It is rudimentary in Tatusia, absent in Pholidotus and Dasypus,|| 
while in Orycteropus{ Galton found it occupying the whole interosseous 
space, though Humphry found it small. Galton found it in Cyclo- 
thurus** ag in Orycteropus. 
. Macalister notes it as absent in Manis, and as reaching the whole 
length of the forearm in Myrmecophagat++. 
The pronator teres in Edentata is always inserted into the distal 
part of the radial shaft for an extent varying from one-third (Chlamy- 
dophorus) to two-thirds (Janis). The coronoid head is invariably 
absent.** 
Macalister’s paper{{ on the Pronator muscles in Vertebrates may be 
further consulted on the morphology of these muscles. 
M. flexor carpi ulnaris (figs. 6, 7, 9, 12,13, 14, and 15 fie.w.). 
This muscle arises by two very distinct heads—one from the 
olecranon, the other from the entocondyle. Just above the wrist 
these bellies unite to form a strong tendon, which is first 
developed upon the superficial aspect of the muscle, and is united 
with the overlying aponeurosis of the tendon of insertion of the 
latissimus dorsi. The tendon is inserted into the elongated pisi- 
form bone near to its base (figs. 14 and 15). 
At their origin the two heads of the muscle are in relation 
with the distal border of the M. anconeus internus, and together 
*xxxiii., page 337. fiv., page 17, and xxxvi., page 130. { xxix., page 
162. §xxvii., page 253, and xxiv., page 39. || xxvii., page 253, and XIV. 
page 546. {I xv., page 586. ** xvi., page 253. tt xxxv., page 504. {{ xxxiil., 
page 335. 
