182 EDWARD L. RICE 
clearly indicated in my sections. Posterior to the fenestra 
septi the limits of the three elements are not well marked, as the 
fusion is very complete; above the posterior part of the fenestra 
the two plates of the solum (fig. 24, sol.s-s.) appear distinct, 
although closely approximated. They are separated only by 
connective tissue; the fenestra is thus rather a notch in the 
upper edge of the septum, as it is closed dorsally by the solum 
alone. <A little further forward a rather indefinite mass of 
cartilage is interpolated between the plates of the solum, although 
apparently distinct from each; still further forward, at the limit 
of the fenestra, this cartilage may be clearly traced into the 
recompleted septum. Gaupp’s interpretation of the solum as a 
paired anlage is thus well corroborated by my observations. 
The posterior third of the solum is broad, the anterior two- 
thirds narrow (fig. 3.), but the transition is not so sudden nor 
the difference so striking as in Lacerta. The upper edge of the 
broader posterior portion is noticeably thickened and may well 
be interpreted as the forward continuation of the taenia mar- 
ginalis of the temporal region. In Lacerta this thickened margin 
is carried somewhat further forward as a freely projecting spur 
alongside of the narrowing solum; this forward projection is 
not recognizable in stage 5 of Eumeces, but 1s very apparent in 
other series, both earlier and later. The thin plates of the solum 
are more or less fenestrated; some of the larger fenestrae are 
shown in figures 1 and 3, but the smaller ones were lost in the © 
modeling. A similar fenestration of the solum supraseptale is 
recorded by Kunkel (’12 b) in Emys and by Nick (12) in Der- 
mochelys, Chelone, and Chelydra. Nick suggests a possible 
homology of these perforations with the fenestra epioptica of 
Lacerta; their occurrence together with the fenestra epioptica 
in Kumeces speaks against this view, while their extreme irregu- 
larity indicates that they are without special significance. 
-Anteriorly the narrow plates of the solum supraseptale, freeing 
themselves from the interorbital septum, pass continuously into 
the cartilagines sphenoethmoidales (fig. 1, c.sph-e.) of the ethmoid 
region, discussed on page 184. 
