410 



CRANIA FROM THE MOUNDS OF FLORIDA. 



Basio-opticon. This is the distance from the basion to the optic foramen. It 

 is an approximation to the length of the base of the brain in the middle cerebral 

 fossa ; the maximum in Seminole skulls being 61 mm. and the minimum 49 mm. 



Optico-nasion} This is the distance from the posterior border of the optic 

 foramen to the nasion, and is an approximation to the base of the brain in the 

 anterior cerebral fossa, and also to the antero-posterior diameter of the face-region 

 at the level of the nasion. Taken with sliding rule it will be observed to be 

 a fairly constant measurement, the maximum in Seminole skulls being 54 mm. 

 and the minimum 49 mm. 



Vomero-bregmatic. This is taken between the union of the vomer and basi- 

 sphenoid bones and the bregma. It indicates the point of union of the anterior and 

 posterior frontal segments. When contrasted with the basio-bregmatic it would also 

 show the degree of inclination of the basilar process if it were not that it is a 

 vertical measurement, while the one last named is oblique. Nevertheless the two 

 are naturally to be contrasted, and are thus placed here in parallel columns since 

 they are widely separated in the table. 







Basi-bregmatic. 



733 . 124 



698 







139 



,105 







136 



730 







130 



,286 







136 



732 







133 



753 







140 



Vomero-bregmatic . 



Basi-bregmatic. 



Vomero-bregmatic 



124 



604 . . 



145 



130 



122 



456 . . 



145 



126 



118 



708 . . 



135 



120 



115 



726 . . 



132 



115 



119 



707 . . 

 Average 



138 



119 



121 



118 



136 



121 



Least alisphenoid and bi-exoccipital diameters. These are contrasted in an 

 attempt to place the narrowest part of the norma basilaris alongside of the widest. 

 I exclude here the bi-mastoid diameter as being less exact. The least alisphenoid 

 diameter is taken between the alisphenoicls at the union of the ascending with the 

 horizontal limb of the greater wing of the sphenoid bone ; the bi-exoccipital between 

 the suture lines uniting the exoccipital with the ecto-petrosal direct to the inner 

 side of the base of the mastoid process. The differences between these measure- 

 ments vary remarkably. 



Squamosal height. The height of the squamosa is taken from the auricular 

 point to the top of the squamosa in order to contrast the Seminole crania with 

 the Moore crania, in which group the squamosa was of low dimensions. 



Bi-?nastoid diameter. Taken between the tips of the mastoid processes. An 

 unimportant measurement here introduced, not because it is essential, but because 

 it has in a sense become conventionalized. 



Palatal measurements. The manner of taking these measurements and the 

 reasons thereon are stated in Section 6. 



1 The basio-opticon is the same as the " foramiuo-optic line" of Cleland. The optico-nasion is 

 the "orbital length" or "frontal depth" of the same writer (see J. Cleland, Phil. Trans., 1869, 117). 



