THE SKULL THE CRANIUM 



303 



FIG. 222. 



below (1"). The lower surface, also seen on the outer aspect, is deeply 

 concave, and receives the upper part of the second piece (Fig. 220, 

 scroll 2'). 



The inner surface (Fig. 

 224) is divided into two 

 parts by a raised curved 

 line extending from near 

 the upper anterior almost 

 to the lower posterior 

 angle. The superior pos- 

 terior triangle is swollen, 

 and appears on the inner 

 aspect as the first scroll 



(!'). The lower anterior LATERAL ETHMOID, EXTERNAL SURFACE. PARTS NUM- 

 BERED, LARGER SCROLLS SHADED. 



triangle is depressed, es- 

 pecially in front, and fits over the second inner scroll, in', the upper 

 part of the mesial piece (Figs. 220, 228). 



FIG. 223. 



Partition, 1. 



First Outer Scroll, 1". 



First Inner Scroll, T. 



Attachment to Cribriform 

 Plate. 



Receives Scroll 2'. 



FIRST PIECE OF LATERAL ETHMOID, OUTER ASPECT. 



The second piece resembles the first in general shape, but is 

 smaller and the posterior end is narrower. Its outer surface (Fig. 

 225) is formed by the median partition, 2, with the scroll 2' above 



FIG. 224. 



Partition, 1. 



First Inner Scroll, 1'. 

 Attachment to Cribriform Plate. 



Receives Second Inner Scroll, m! . 



FIRST PIECE OF LATERAL ETHMOID, INNER SURFACE. 



and the scroll 2" below. Its concave inferior surface fits over the 

 fourth outer scroll, the inner and upper part of the third piece (Figs. 

 220, 229, scroll 3'). 



