238 Transactions.— Zoology. 
and coraco-brachialis. The supra-spinatus, teres and infra-spinatus form a 
broad mass arising from the scapula, and, still continuing a broad mass, pass 
over the shoulder joint to the outer and upper part of the humerus. 
The serratus magnus arises from the fourth and fifth ribs, and from the 
h;emapophyses passes forward to the posterior border of the cartilaginous 
and bony part of the scapula. The more numerous and powerful fibres are 
inserted into the bony portion. The subscapularis large thick muscle takes 
its origin from the inner surface of the bony and cartilaginous scapula and 
is inserted into the humerus. No rhomboidei (Günther) The biceps 
brachii arises by one head from the scapula and humerus, by the other from 
the surface and margin of the cartilaginous coracoid ; opposite the shoulder 
it narrows into a thin tendon, and over this the tendon of the pectoralis- 
major plays freely ; becoming fleshy again it travels down the arm, its 
tendon of insertion piercing the flexor and extensor muscles of the fore-arm 
and reaching the ulna. The coraco-brachialis arises from the cora coid, and is 
inserted down the whole length of the humerus as far as the external 
condyle. A large flat muscle arises from the coracoid bone near its junetion 
with the scapule and is inserted into the head of the humerus—epicoraco- 
humeral. In Iguana Mivart describes a similar muscle. The triceps arises 
by only two heads, one attached to the constricted part of the scapula, the 
other a long fleshy slip coracoid. They join, and forming one muscle are 
attached all down the posterior surface of the humerus and into the 
. olecranon, 
Throat muscles. 
A broad strong sheet of fascia arising from the clavicle passes forward, 
covering in the under surface of the neck and becoming attached along the 
whole length of the inner surfaces of the mandibles, becoming much thinner 
near their junction, and is connected by loose cellular tissue with the deeper 
muscles. The mylo-hyoid is well developed ; it stretches from mandible to 
mandible. The sterno-cleido-mastoid arises fleshy from the whole of the 
clavicle, passes forwards and upwards to be inserted into the mastoid and 
parietals. It may easily be divided into several portions looking like 
distinct muscles. By two heads the omo-hyoid arises, one from the outer 
end of clavicle, the other from the inner. In Iguana this muscle arises by 
one broad head. It wends inwards to the mesial line and passes upwards 
to be inserted into the laryngeal cartilage. It is separated by cellular tissue 
from its fellow-muscle, and internally is closely connected with the trachea. 
It is probably what in man is distinguished as sterno-thyroid and omo- 
hyoid. The genio-hyoid is a small muscle inserted with its fellow into the 
mandibles near their junction. The stylo-hyoid arises from the mastoid 
and ends in a remarkably long tendon, which curves round the posterior 
