548 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
The levator anguli scapule (L.a.s, fig. 20) much resembles the cervical slips of the 
serratus magnus, but isa much broader and larger muscle, and partly hides the above 
towards the atlas. It has origin by a short, flat tendon, coming from the transverse 
process of the atlas; and the muscular slip continued therefrom proceeds to the spine 
of the scapula, where it is inserted into the lower third, or that portion unoccupied by 
the rhomboideus capitis muscle. 
The sterno-mastoid (St.m, fig. 15) is apparently a single muscle, although there does 
exist a sulcus, or line of division, in the fibres composing it, but which does not continue 
the whole length of the muscular belly. Its origin or cephalic attachment is from the 
exoccipital bone to the paramastoid process; and the sternal insertion is into the upper 
and outer surface of the manubrium. 
Sterno-hyoid and sterno-thyroid.—These have a common origin. Unitedly they form 
a very strong slip or fleshy band, an inch and a half broad, which proceeds forwards 
on the neck (St.h & ¢, fig. 33), lies in close contact with, and is attached by cellular 
membrane to, the trachea. ‘Two inches behind the posterior border of the cricoid 
cartilage the superficial muscular fibres separate, and pursue a course inwards and 
forwards, narrowing as they pass over the thyroid cartilage; this the free portion of 
the sterno-hyoid muscle is inserted into a thin transverse fibrous septum, placed over 
the basihyal, and dividing the muscular fibres of the root of the tongue from those of 
the neck proper. 
Equal in volume to the foregoing, the sterno-thyroid on its divergence from the mus- 
cular head common to it and the last mentioned has its fibres directed slightly outwards 
and forwards, being only partially covered by the sterno-hyoid, but nearly hidden by 
the equally broad omo-hyoid. ‘The insertion of the sterno-hyoid is the posterior and 
inner margin of the curved line of the thyroid cartilage, beside its lower angular border. 
The origin of the thyro-hyoid intervenes between the attachment of the sterno-hyoid 
and the inferior constrictor, its thyro-pharyngeal portion. The outer border of the 
sterno-thyroid, for a short distance, touches the cesophagus, and covers almost entirely 
the small-sized thyroid gland. Anterior to this last it lies upon the crico-thyroid 
muscle, being attached to the thyroid cartilage outside the superficial anterior fibres 
of the crico-thyroid muscle. 
The internal jugular vein, common carotid artery, and large pneumogastric nerve lie 
outside the sterno-thyroid muscle. 
The longus colli, as in Man, consists of two portions; these differ slightly, however, 
in their attachments. ‘Together they form a very powerful fleshy muscle, so much so 
that the tendons of attachment are almost entirely hidden by the muscular fibres. 
The first anterior or superior oblique portion (fig. 24, Z.c') has a narrow origin from 
the body of the atlas, at its posterior portion, and from the ventral surface of the body 
of the third cervical vertebra. his belly, as it extends backwards, has tendinous slips 
of insertion into the transverse processes of the third, fourth, and fifth cervicals. The 
