338 MESSRS. MURIE AND MIVART ON THE [Apr. 11, 
The sudclavius is absent ; in this respect the Hyrax differs from the 
Guinea-pig. The muscle which we call the sterno-scapular evidently 
comes under the denomination swbclavius in Meckel’s* work. 
Sterno-scapular.—This rather uncommon muscle arises from the 
sternum, immediately in front of the origin of the pectoralis minor, 
and, passing over the scapulo-humeral articulation, continues along 
the upper (anterior) border of the scapula, to be inserted into its 
anterior superior angle (figs. 3 & 4, S. sc.). 
This muscle is very interesting, because it occurs in the Pig and 
other Ungulata+t, not, however, that it is exclusively confined to that 
group, as we found it existing most unmistakeably in the Guinea-pig, 
which we examined on purpose. 
There is a muscle described by Meckelf as existing in the Hare, 
Porcupine, and Agouti, extending from the spine of the scapula to 
the sternum, which evidently is our sterno-scapular, but which he 
considers rather belongs to the subclavius than forms part of the 
trapezius, as Cuvier § thought. 
The deltoid is very slightly developed, as occurs also in the Ungu- 
lata. It seems to consist of two portions, the first arising by ten- 
dinous fascize from the inferior border of the infra-spinatus, and in- 
serted by a broad tendinous fascia into the outer border of the hu- 
merus, below its head (fig. 5, D.). 
_The second part, much smaller than the first, arises from the 
great tuberosity of the humerus, and not from the scapula, and is 
inserted into the deltoid prominence immediately internal to the inser- 
tion of the first head. 
Our description seems to agree with Meckel’s|| observation as to 
the deltoid being divided into two muscles. 
The supra-spinatus muscle is very strong, and with the usual origin, 
but, on account of its bulk, occupying more space than the mere 
fossa (fig. 5, S.sp.). It ends in a forked manner, and is inserted 
into the whole inner side of the greater tuberosity, and outer margin 
of bicipital groove of the humerus. Meckel observes that the con- 
sequence of this double insertion in the Horse, Camel, and Hyrax 
is only to raise the arm, without carrying it outwards, in this way 
being an auxiliary to the deltoid]. 
The infra-spinatus arises from the infra-spinous fossa, the fibres 
being delicate towards the cartilaginous portion of the scapula. It 
contains, near the neck of the bone, a strong tendon within its sub- 
stance, and the muscle is inserted into the great tuberosity of the 
humerus (fig. 5, I. sp.). 
The subscapularis does not cover the subscapular fossa. It arises 
by four or five digitations, which do not reach the whole length of the 
scapula. The insertion is into the lesser tuberosity of the humerus. 
The ¢eres major is long and strong; as usual, it arises along mar- 
* Loc. cit. p. 260. 
+ Huxley, in his recent Hunterian Lectures for 1865. 
Loe. cit., pp. 259, 260. 
§ Lecgons d’Anat. Comp. vol. i. p. 373. 
|| Loe. cit. p. 226. ¥ Loc. cit. p. 259. 
