264 ZAGLOSSUS. 
angle. Possibly this anterior part may represent an acromio-clavotrapezius 
The insertion seems to be slightly less extensive in the Echidna. 
The posterior portion of the trapezius, perhaps the homologue of the spino- 
trapezius is a flat sheet, nearly an equilateral triangle in outline, arising by a 
very thin tendinous sheet from the dorsal spines of the tenth thoracic to the 
second lumbar vertebrae. It thickens greatly as it narrows to its insertion, 
some 20 mm. in length, on the anterior edge of the scapula (the region corre- 
sponding to the spine). 
As in the Echidna, the rhomboideus is a single muscle, arising under the 
trapezius from the parietal margin of the skull, above and slightly in advance 
of the ear, nearly to the midline of the cranium, and posteriorly underneath 
almost the entire length of the trapezius. It thickens as it passes laterally to 
its insertion along the entire vertebral border of the scapula. 
The levator scapulae ventralis arises by two heads:— (1) a slightly tendinous 
attachment from the basioccipital and (2) a strong muscle mass from the ventro- 
lateral portion of the atlas and axis. The insertion is at the anterior edge of 
the scapula at the point of union with the clavicle and thence dorsally for about 
20mm. Mivart (1866) in the Echidna did not note the extension of the origin 
to the axis, but otherwise the muscle appears to be similar. 
The occipitoscapularis is a narrow ribbon-like muscle from the mastoid 
region just posterior to the ear. It is inserted along the vertebral edge of the 
scapula, beginning about 10 mm. from the gleno-vertebral angle and extending 
anteriorly about twice that distance. Apparently Mivart (1866) and Westling 
(1890) did not find this muscle in the Echidna. ns 
The cleidomastoideus is wanting as in the Echidna. 
The latissimus dorsi has already been mentioned in connection with the 
cutaneous muscles. It may be considered as consisting of three parts of which 
the most anterior only has the usual relations. This arises by six or seven digi- 
tations from the first seven thoracie vertebrae, and passes to a strong tendon 
that inserts upon the most posterior part of the tuberosity of the humerus. Its 
tendon is joined by that of a narrow muscle arising from the ridge on the scapula 
dorsal to the glenoid cavity. This latter muscle is of doubtful homology, and is 
found likewise in the Echidna where, however, it originates instead ‘from the 
posterior extremity of the vertebral margin of the scapula.” Mivart calls it 
a dorso-epitrochlear (?), or possibly a separate portion of the teres major. West- 
ling (1889, p. 14), however, considers it a part of the latissimus dorsi that is 
not homologous with any separate muscle in other animals. In support of 
