20 ANTHROPOLOGY. 
case with a flattened base, inclosing a cavity of similar shape, cavum — 
cranw (pl. 121, g. 5), narrowest anteriorly, but wider in the middle than 
behind. The precise shape of the cranium, however, depends upon that 
of the brain, and consequently varies with the individual. In the face are 
found the orbits or cavities for the eyes, those for the nasal apparatus, and 
the mouth. 
The bones of the skull are mostly united by the articulation known as 
the sutura. The coronal suture joins the frontal bone with the two parietal, 
and extends from one temple to the other across the skull. The frontal 
suture 1s not always seen, as it usually becomes obliterated with age. When. 
present, however, it extends along the upper median line of the cranium, 
from the base of the nose to the coronal suture, and divides the two frontal. 
bones. The sagittal suture unites the two parietal bones along the median 
line in the continuation of the frontal suture, and extends from the coronal 
to the lambdoidal suture. This lambdozdal suture unites the occipital to.the 
parietal bones by its upper half, and the occipital to the temporal by the 
lower. The squamous suture unites the temporal to the parietal bones, and 
occupies the side of the head. 
The outer surface of the head may be conveniently divided into four 
regions. The superior, or the vertex, is smooth and even, without any 
remarkable features attending it. The /ateral regions are each divided 
into two, the anterior or temporal, and the posterior or mastoid; the meatus 
auditorius externus is between the two. The znjerior region extends from 
the nasal notch in the frontal bone to the occipital protuberance, and is 
bounded laterally by the zygomatic arches and by a ridge which is con- 
tinued from these processes around the skull with but little interruption. 
This region may be divided into three portions, anterior, middle, and 
posterior. The anterior basilar region extends from the superciliary ridges 
of the frontal bone to the roots of the pterygoid processes of the sphenoid; 
it presents the nasal spine and process of the os frontis, bounded by their 
angular processes before and by the orbital plates of the sphenoid behind. 
In this division are the supra-orbital, the anterior and posterior orbital 
holes, the openings of the frontal and ethmoidal cells, the optic and lacerated 
foramina of the orbits, the vidian canals, and the foramina rotunda. The 
middle division extends from the roots of the pterygoid to the styloid 
processes of the temporal bones; it presents the, azygos process: of the 
sphenoid, the basilar process of the occipital, the anterior points of the 
petrous portion of the temporal bones, the spinous processes of the sphenoid, 
and the glenoid cavities of the temporal bones. The foramina, or holes in 
this division, are the ovale, spinale, carotidum, auditorus éxternus, and the 
glenoid; the eustachian canals are external to it. The posterior division 
extends from the styloid processes of the temporal to the tuberosity of the 
occipital bone; it presents the foramen magnum, the two condyles, the 
jugular ridges, the styloid processes of the temporal bones, surrounded by 
the vaginal processes, the mastoid processes, the digastric grooves, the 
inferior and superior transverse arches, the spines, protuberance, and 
depressions of the occipital bone. The foramina in this division are the 
7126 
