546 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
site the third dorsal vertebra forwards to near the occiput, being broadly inserted into 
the occipital bone. The latter (Sp.co) arises by a single slip from the sides of the fourth 
and fifth dorsal vertebral spines, and besides by origin from the zygapophyses of the two 
anterior and the last three cervical vertebrae. The muscle increases very considerably in 
breadth as it proceeds forwards; but its belly continues in a straighter line than the 
splenius capitis. It ultimately joins the last-mentioned muscle; and the two form a 
common mass at their insertion, which, as it expands, stretches from the occipital pro- 
tuberance to the paramastoid process. 
The compleaus, along with the biventer cervicis muscle, covers nearly entirely the 
layer of the neck. Strictly speaking, these ought to be considered one muscle; but it 
is more convenient, and may be clearer, to describe them as separate heads. 
First, the complexus (complexus major) (fig. 22, Co), considerably the larger portion 
ot the two, arises by digital fleshy slips from the metapophyses of the third, fourth, 
fifth, sixth, and seventh cervical vertebre ; and these, uniting, pursue a course inwards, 
upwards, and forwards. The single fleshy belly is inserted into the occiput outside the 
fossa which lies close to the median occipital crest. This broad insertion is slightly 
tendinous superficially. 
Second, the biventer cervicis (complexus minor) (/7.c) is a much longer but narrower 
slip, and forms the spinal border of the complexus. It arises by slips from the fifth, 
second, and first dorsal spines, and is inserted along with the fibres of the complexus into 
the occiput ; but those of the biventer cervicis are attached not outside, but within the 
fossa itself, at the side of the median occipital crest. 
Rectus capitis posticus major (fig. 23, R.p.ma) has a considerable volume of fleshy 
fibres, and, from the form of the occipito-nuchal region, a somewhat elongated thick 
fusiform shape. Its points of attachment, however, do not vary from what is usually 
found in other Carnivora. Behind, its origin from the axis is narrow and muscular; and 
it rests here upon the lamine close to the spine. Anteriorly, its occipital insertion is 
likewise tolerably muscular, or there are but very short tendinous aponeurotic fibres. 
The rectus capitis posticus minor, lymg beneath the last and partially hidden by it 
(£.p.mi), is relatively smaller, but, notwithstanding, is tolerably fleshy. It stretches, as 
ordinarily, betwixt the atlas and the occiput. 
The rectus lateralis (R.l), by some anatomists regarded in Man as one of the inter- 
transversales, is here a short, broad, and distinct muscle. Its cervical attachment or 
origin is the inferior or anterior surface of the transverse process of the atlas; and it is 
inserted into the occiput, behind the paramastoid process, just posterior to the hinder 
end of the digastric muscle. 
The obliquus capitis superior (O.s) extends from the transverse process of the atlas 
to the occiput. Like the other short deep muscles of the neck in this animal, it is 
strong and fleshy. 
Of nearly equal size to the last is the obliguus capitis inferior (0.7), which is placed as 
