180 DR. J. MURIE ON THE FORM AND STRUCTURE OF THE MANATEE. 
putably traced from origin to insertion; the anterior remnant remained, its posterior 
fibres being lost among the tangled vessels and deep cervical fascia. Stylo-hyoid and 
stylo-pharyngeus are somewhat adherent, the latter broad and well developed. The 
digastric, single-bellied and broad anteriorly, fills the hollow at the inflection of the 
mandible, and thence passes rearwards to the junction of the stylo-hyal with its cranial 
cartilage. The horseshoe-shaped submaxillary gland abuts on its inner, and the parotid 
on its outer margin. The stylo-glossus is large, and the constrictores superior and medius 
are full and fleshy. The thin sheet of fibres of the levator palati cover the Eustachian 
enlargement, and are spread out and lost in the posterior palate. The tensor palati, 
better marked, arises near the tympanic bulla, passes round the pterygoid process, and, 
by a strong flat tendon, widens out on the posterior palatal membrane. The pterygoidei 
and plexuses lie outside. The palato-glossus is moderately broad, and the palato- 
pharyngeus fairly developed. Mylo-hyoidei, as a thin fleshy plane, stretch and fill the 
angle betwixt the ramal bodies. Long and thin genio-hyoidei pass from the basihyal 
to the concavity of the chin, a vascular plexus existing beneath. A distinct hyo-glossus 
was not observed; but genio-hyo-glossi and lingualis are both well represented. 
VIL. Tue Nervous System. 
When treating of the interior of the skull I dwelt upon the dura mater as it lines 
the bones and the foramina piercing it basally. Its upper surface, when the calvarium 
is removed, is tolerably smooth, a superior longitudinal sinus being but faintly indicated. 
On each side the membrane is tucked into a deep Sylvian sulcus, which traverses well 
across the cerebrum; another, marked but shallow, depression is manifest about the 
centre of the posterior cerebral division. The dura mater is tough, strong, and rough at 
the vascular sinuses and plexuses. While it is intact, the cerebrum leaves the bulging 
cerebellum uncovered to a considerable extent. 
The encephalon of the younger male was so destroyed as to be unfit for examination. 
While the membranes surrounded the brain of the female specimen a tolerably accurate 
idea of the cerebral contour was got; but on raising the dura mater the brain itself was 
found to be softened, and with difficulty extracted. No measurements or weight were 
taken, but the whole placed in spirit as rapidly as possible. A cast of the cranial 
cavity with its enclosed dura mater was subsequently made; and by the help of this 
cast and the shrunken brain the sketches (Pl. XXV.) were drawn. 
I may remark, en passant, that the views (figs. 31 & 33) of the upper and under surface 
of the brain slightly exaggerate the relative breadth of the anterior to the posterior 
lobes, by the former not being approximate enough at the longitudinal fissure. With 
regard to dimensions, the drawings are given as nearly as possible of the size of nature ; 
the cranial interior, its model, and the preserved brain respectively yielding the scale 
of relations. 
From above and below, the outline of both cerebral hemispheres is somewhat qua- 
