20 ANTHROPOLOGY. 



case with a flattened base, inclosing a cavity of similar shape, cavum 

 cranii {pi. 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 ]oms the frontal bone with the two parietal, 

 and extends from one temple to the other across the skull. The frontal 

 suture is 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 lambdoidal 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 

 oceupies 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 lateral regions are each divided 

 into two, the anterior or temporal, and the posterior or mastoid; the meatus 

 auditorius externus is between the two. The inferior 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 externus, 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 

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