EXPLANATION OF THE PLATES. 



PLATE I. 



Beginning with the most aberrant forms, we have the 

 American, whereof the Aturian Palta or Titicaca Flat- 

 heads form the type. It is so distinct, that its having a 

 common origin with the forms of the Old Continent is not 

 satisfactorily established, since the oblique headed Peru- 

 vian, and the depressed headed Chinook are mere artificial 

 imitations of the typical head. That this is not itself the 

 result of contrivance, is exemplified in the figure of a Titi- 

 caca 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 pre- 

 sents the additional bone (os incse) 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 ver- 

 tical view of a Negro's skull, pointing out the small com- 

 parative breadth to the depth, and the projection of the 

 face approaching the Titicaca form. Both have the frontal 

 bone carried high up the dome, though not in the same 



