MR. ST. G. MIVART ON THE ANATOMY OF ECHIDNA HYSTRIX. 383 
this muscle as the representative of the subclavius. Meekel is silent as to both; but 
Owen ! says that both a pectoralis minor and a subclavius are inserted into the coracoid 
in the Ornithorhynchus. 
* Epicoraco-humeral” (Plate LII. fig. 2, E.H).—A small muscle, with a few ten- 
dinous fibres at its insertion, arises from the outer surface of the epicoracoid, lying 
deeper than the interclavicle, the outer margin of which is superficial to it. It is 
inserted into the humerus, in a groove situated between the prominence for the insertion 
of the pectoralis and that for the insertion of the sup» (us, and also on a ridge 
running thence downwards. This muscle answers neither by its origin nor insertion 
to either the pectoralis minor or to the subelavius. It is evidently the muscle described 
and figured by Meckel? as the anterior portion of the deltoid; but, in the Echidna, we 
have, in addition to this muscle, another, which appears to be wanting in the Ornitho- 
rhynchus (judging from Meckel's figures), and which is evidently the anterior part, if not 
the whole, of the deltoid. Inasmuch as the epicoracoid is the representative in the 
shoulder-girdle of the pubis in the pelvie one, it is not impossible that this muscle 
may be the serial homologue of the pectineus, or of the obturator externus—more pro- 
bably the former, on account of its insertion. 
The muscle which, in the common fowl, arises from the inner border of the coracoid 
and the outer margin of the clavicle, and is inserted into the great tuberosity of the 
humerus immediately above the attachment of the great pectoral, greatly resembles the 
muscle which I have provisionally called * epicoraco-humeral " in the Echidna. 
Serratus magnus and levator anguli scapule (Plate LII. fig. 1, s.M).—These muscles 
together form one large and thick layer, arising from the first four ribs and from the 
transverse processes of all the cervical vertebræ from the seventh to the axis inclusive, 
and being inserted into the whole vertebral border of the scapula and the uppermost 
fourth of its spine, and into the vertebral surface of the scapula, for some distance within 
the margin. 
There is much tendon interspersed in the muscular mass, the tendons being visible on 
that surface of the muscle which is turned towards the neck and trunk. The tendon 
arising from the axis is strongest and most marked ; that from the third cervical vertebra 
almost equals it; the more posterior ones are less and less conspicuous. 
The omohyoid is long and very slender; it arises from the inner surface of the sca- 
pula, very deep down, but in its normal relation to the supra-spinatus muscle; it is 
inserted into the hyoid. | 
Levator clavicule (?).— There are two flat and rather thin bands of muscular fibre 
hr are closely connected at their origin, and together appear to represent this 
muscle. 
The first of these arises, by a tendinous aponeurosis, mainly from the ventral surface 
9f the atlas, but partly also from the basioccipital, and is inserted into ihe end af the 
acromion, and a little also into the outermost end of the clavicle. At its origin it is 
closely connected with, but superficial to, the next muscle. 
* Loe. cit, p. 381. 2 Loc. cit. p. 26, and tab. v. no. 19; and Owen, Joc, eit. p. 381. 
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