560 



ANATOMY OF VERTEBRATES. 



372 



is impressed on the inner side by the lateral sinus; e is the 

 ^ squamous ' and a the ' coronal ' suture. The frontal, F, is 

 joined by the "■ external angular process/ i, to the malar, which, 

 with the alisphenoid, divides the orbital from the temporal fossa. 



The alisphenoid, s, and co- 

 articulated portion of pa- 

 rietal, /, divide by a broader 

 tract the frontal, F, from the 

 temporal, T, as compared 

 with the Australian. In 

 more intellectual races the 

 cranial cavity is relatively 

 larger, especially loftier and 

 wider. The fore-parts of the 

 upper and lower jaws, con- 

 comitantly with earlier wean- 

 ing, are less produced, and 

 the contour descends more 

 vertically from the longer 

 and more ])rominent nasals. 

 The ascending ramus of the 

 mandible, K, is loftier. The 

 malar, i, is less protube- 

 rant, and the mastoid, m, more so. 



The vertical longitudinal section, fig. 373, of a well-formed 

 European skull, best exemplifies, in comparison with fig. 395, the 

 characteristic proportion of the human cranial cavity. The basi- 

 occipital, 1, coalesces with the basisphenoid, 5, and this with the 

 presphenoid, such base of the cranium rising as it advances. The 

 chief part of the foramen magnum is formed by the exoccipitals, 2 ; 

 the plane of the foramen looks downward, with a slight inclination 

 forward. The superoccipital, 3, is expanded and bulged outward 

 by the cerebellum and posterior cerebral lobes. The petrosal, 

 perforated by the foramen auditorium internum, is 16 ; betAveen 

 this and the alisphenoid, 6, is the squamosal ; they contribute but 

 small proportions to the cranial walls, which are chiefly due to the 

 expanded neural spines called 'parietal,' 7, and 'frontal,' ii, with 

 the above-mentioned superoccipital, 3 : i4 is between the 'orbito- 

 sphenoid ' (' lesser ala of the sphenoid,' in anthropotomy) and the 

 coalesced 'prefrontals '('perpendicular plate of the ethmoid ' with the 

 ' crista galli,' ib.). The rhinencephalic fossa is shalloAv, ill-defined, 

 relatively small, and floored by the ' cribriform plates.' In the 

 nasal cavity the inferior ' turbinal,' d, and the ' middle turbinal,' c, 



Skull of a well-formed European. 



