1865.] MYOLOGY OF HYRAX CAPENSIS. 331 
digastric, and is inserted as usual; it is strong and relatively thick, 
as Meckel says *. 
The stylo-glossus is very well defined, arising from the anterior 
margin of the paramastoid, and having the usual insertion into the 
tongue. 
On the left side we observed a long narrow muscular slip, arising 
from the paramastoid by a delicate tendon, and descending the neck ; 
but its insertion we could not ascertain. This we took to be the 
stylo-pharyngeus. 
Digastrie.—This is very large and much flattened, and lies closely 
appressed to the concavity inside the mandible, behind and beneath 
the mylo-hyoidean ridge. It arises from the paramastoid, along 
with the three last-mentioned muscles and the third head of the s¢erno- 
cleido-mastoid ; but the digastric occupies the greater portion of that 
process. It is inserted inside and along the whole of the inferior 
margin of the mandible, as far as a little behind the symphysis, de- 
licate fibres running on almost to the symphysis itself (see fig. 2, D.). 
Though this muscle is not exactly double-bellied, yet there is more 
or less of glistening tendon on both sides posterior to its middle. 
Cuvier'’s description is correct as far as it goes+, also that of Meckelt, 
who particularly mentions its great width. 
The sterno-hyoid and thyroid muscles had their usual insertions 
into the hyoid bone and thyroid cartilage; but their origin was de- 
stroyed. All the other muscles connected with the larynx were well 
developed, except the omo-hyoid, which we did not find. Meckel§ 
says that it (le seapulo-hyotdien) is wanting. 
The fibres of the platysma myoides are strongly developed, and 
posteriorly the muscle is in intimate union with the eletdo-mastoid 
(or cephalo-humeral), which it overrides (fig. 3, P. m.). 
Sterno-cleido-mastoid.—First part, cephalo-humeral or cleido- 
mastoid, strong and long, arises from the occiput, and is inserted 
into the ulna in common with the biceps (figs. 3 & 4, C.A.). At 
the upper part, as already mentioned, its union with the platysma 
myoides is so close that the line of demarcation is hardly to be defined. 
On comparing the muscles of a Guinea-pig (Cavia) with those of 
our Hyrax, we found the sterno-cleido-mastoid had nearly the same 
origin and insertion at the upper part of the humerus ; however, it 
differed from the Hyraz in haying a distinct attachment to a rudi- 
mentary clavicle. 
The second part, or true sterno-mastoid, is very thick and bulky, 
and with an unusual origin, which may perhaps have led to its being 
confounded with the digastric ||. It arises by a strong tendon from 
the summit of the posterior margin of the ascending ramus of the 
mandible, and also by fascize from the posterior border of the same, 
and from the surface of the masseter. It is inserted into the manu- 
brium, and joins its fellow of the opposite side in the lower half of the 
neck (fig. 4, S. ed. m. 2). 
* Anat. Comp. tome viii. p. 507. t Op. cit. tome iv. part i. p. 94. 
t Op. cit. tome viii. p. 478. § Loe. cit. p. 507. 
|| Owen, Proc. Zool. Soc. 1832, p. 207. 
