REPORT ON THE MARSUPIALIA. 5 



In the Thylacine the connections of the cleido-mastoid are very different. At the 

 root of the neck it stands widely apart from its colleague the sterno-mastoid. Anteriorly 

 it is attached to the mastoid process under cover of the sterno-mastoid. From this it is 

 carried backwards towards the shoulder in the form of a narrow fleshy band. Reaching 

 the rudimentary clavicle its fibres are partly inserted into the inner half of this bone, and 

 partly continued into the clavicular deltoid (PI. I. fig. 4, cm.). 



Latissimus dorsi. — This muscle has a shape very simdar to that of the corresponding 

 muscle in man. It arises from the spinous processes- of all the dorsal vertebrae with the 

 exception of the first and second, from the lumbar aponeurosis and by a single digitation 

 from the last rib. From this wide origin it sweeps downwards and forwards so as to 

 overlap the posterior angle of the scapula. In no case does it receive fasciculi from this 

 bone. As it approaches the humerus it becomes much narrower, but, at the same time, 

 what it loses in width it gains in thickness. In the Cuscus and Phascogale the insertion 

 of the latissimus dorsi is identical ; in the Thylacine it is somewhat different. In all it 

 is more or less connected with that of the teres major. 



In Cuscus (PL II. fig. 4, l.d.) and Phascogale the latissimus dorsi, as it approaches 

 its insertion, divides into two parts. Of these the upper and smaller slip which corre- 

 sponds with the anterior margin of the muscle passes behind the other part and joins 

 the posterior margin of the teres major with which it is inserted. The posterior and 

 main portion of the muscle gives off the dorsi-epitrochlear and then ends in a strong 

 flat shining tendon. This proceeds outwards under cover of both heads of the biceps, 

 and is inserted into the bottom of the broad shallow bicipital groove of the humerus. 

 This attachment is separated by a wide interval from the insertion of the teres major, and 

 abuts against that of the pectoralis major. 



In the T/njlacine the teres major and the latissimus dorsi have a common insertion 

 into the humerus through the medium of a strong tendinous band, which arches backwards 

 from the bottom of the bicipital groove. This band is twisted upon itself so that it 

 presents a round, smooth, and corddike posterior border. Into the lower half of this 

 common tendon the teres major is inserted — a few of its fibres, however, obtaining a direct 

 attachment to the humerus immediately below the lesser tuberosity ; into the upper part 

 of the tendon the latissimus dorsi is inserted. 



Dorsi-epitrochlear. — This muscle is present in all, although relatively it is best 

 developed in the Phascogale. It springs from the posterior margin of the latissimus 

 dorsi a short distance from its insertion, and is carried downwards upon the inner aspect 

 of the long head of the triceps. It is inserted in the Cuscus (PI. II. fig. 4, d.e.) and 

 Phascogale into the inner aspect of the tip of the olecranon process. In the Thylacine 

 it joins the triceps near the elbow and is inserted with it. 



Serratus magnus. — In the Cuscus (PI. II. fig. 4, s.m.) only is there any indication of 

 a division of this muscle into a cervical and a costal portion. In the Phascogale and 



