EXPLANATION OF THE PLATES. 



PLATE I. 



Beginning with the most aberrant forms, we have the American, 

 whereof the Aturiau Palta or Titicaca Flatheads form the type. It is so 

 distinct, that it- having a oommoo origin with the forma of the Old Con- 

 tinent is not satisfactorily established, since the oblique-headed Peruvian 

 and the depressed-headed Chinook are mere artificial imitations of the 

 typical head. That this is not itself the result of contrivance, is exempli- 

 fied in the figure of a Titicaca child's head of perhaps the fifth year, 

 which is greatly prolonged, yet less so than another in positive infancy. 

 Both have the orbits more solid than heads of the same age on the 

 eastern continent, and the older of the two presents the additional bone 

 (os incoe) at the back of the head. The oblique-headed Peruvian shows 

 its resemblance to Asiatic figures to be noticed in the sequel. 



PLATE II. 



Offers specimens of the woolly-haired type, the vertical view of a 

 Negro's skull, pointing out the small breadth compared to the depth, and 

 the projection of the face approaching the Titicaca form. Both have the 



