CHONDROCRANIUM OF EUMECES 125 
may also be traced backward for a very short distance as a pro- 
jecting crest (fig. 7; figs. 17 and 18, b.pl’.) along the ventrolateral 
limit of the prominentia recessus utriculi. This rolled edge is 
clearly homologous with the much more conspicuous projecting 
edge of the basal plate in Emys to which, in its various regions, 
Kunkel (12b) gives.the names of crista inferior, crista sub- 
stapedialis, and crista basipterygoidea. The relation to the tri- 
geminal ganglion is the same; but a connection with the well- 
developed processus basipterygoideus is not seen in Eumeces, 
nor has the ridge here any such posterior extension as in Emys. 
Under the name processus subcapsularis, Shiino (714) describes 
a similar structure in the crocodile, and notes that it is also rec- 
ognizable in Gaupp’s figures of Lacerta, but not in those of 
Schauinsland (’00) of Sphenodon. From the fenestra basi- 
cranialis posterior backward the thickened margin of the basal 
plate is everywhere separated from the otic capsule by the fissura 
metotica (figs. 7 and 8, fis.m-ot.), although this fissure is practi- 
cally obliterated, for a short distance immediately posterior to 
the fenestra cochleae, by the contact (not fusion) of a projecting 
angle of the basal plate and the swelling of the otic capsule to 
form the prominence of the posterior ampulla (fig. 7, prom.amp.p.). 
At the posterolateral angles the basal plate connects with the 
occipital arches (figs. 2 and 6, oc.), and, between these arches, its 
posterior margin is greatly thickened in the condylar region 
(figs. 2 and 6, con.). The conditions here are essentially as in 
Lacerta, and also essentially as in the embryonic Echidna skull 
(Gaupp, 08a). In the median line, at the entrance of the noto- 
chord, there is a decided notch (fig. 2, in.i-c.). Compare the 
incisura intercondyloidea of Echidna (Gaupp, ’08 a), the rabbit 
(Voit, ’09 b), the dog (Olmstead, 711), and other mammalian 
embryos. At the sides of this intercondylar notch are two con- 
spicuously projecting domes of cartilage which can hardly be 
other than the homologue of the mammalian condyles. Ventral 
and anterior to the notch the condylar projections are connected 
by a thickening of the cartilage. Thus is formed a continuous 
crescentic or kidney-shaped condylar mass, from which it is 
easy to derive the specialized single condyle of the majority of 
