238 transactions. — Zoology. 



and coraco-bracliialis. 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 

 hsemapophyses 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 (Giinther). 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-bracliialis arises from the coracoid, 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 junction 

 with the scapulae 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 



