CHONDROCRANIUM OF EUMECES 185 
2. Nasal septum 
At the transition from the orbital to the ethmoid region the 
nasal septum is a comparatively low vertical plate with free 
dorsal and ventral margins (fig. 3, sep.na.), but it increases rather 
suddenly in height to meet the nasal roof or tectum. From this 
point to the tip of the snout its height falls off gradually, its 
dorsal margin showing a rather uniform curve, corresponding to 
the profile of the snout. Between the very large and confluent 
fenestrae superiores nasi the dorsal margin of the septum is free 
(figs. 1, 27, and 28). This is not the case in Lacerta, where the 
fenestrae are much smaller, but it holds true for all observed 
stages of Eumeces. Elsewhere the septum is fused with the 
tectum, except, perhaps, for a very short distance at the very 
tip of the nose, where the foramina apicalia (fig. 1, f.ap.) are 
very closely approximated and separated certainly by little more - 
than the septum itself. The ventral margin, on the other hand, 
is free for the greater part of its length, fusing only at the ex- 
treme anterior end with the very degenerate solum nasi (fig. 2, 
sol.na.). Through a considerable distance the lower edge of the 
septum is closely bordered by the paraseptal cartilages (figs. 2, 
25, and 26, c.par.), but in no case is there actual contact. The 
lower outline of the septum is ventrally concave, continuing 
almost exactly the curvature of the corresponding margin of 
the interorbital septum. The curvature of the ventral edge is 
decidedly less than that of the dorsal. 
The ventral edge of the posterior portion of the septum nasale, 
like that of the septum interorbitale, is decidedly thicker than 
its upper part (figs. 25 and 26). Further forward this thickening 
disappears. In this region in Lacerta Gaupp describes a thick- 
ening of the septum in middle height, forming a low longitudinal 
ridge on each side, which supports the median edge of the septo- 
maxillary bone. Thisridge is very slightly developed in Eumeces, 
and is recognizable only in the later stages. In stage 6 the 
septomaxillary (fig. 27, os s-mazx.) is very closely approximated 
to the septum, and, for some distance, comes into actual con- 
tact with this slight thickening, but in earlier stages, even stage 5 
