178 EDWARD L. RICE 
homologized with the taenia marginalis, and for which Fischer 
(01 b) retains the latter name, is usually highly developed. 
On the other hand, the lateral extension of the cavum cranii has 
led to the development of a secondary lateral wall and the further 
degeneration of the primary wall. This is usually described as 
wholly lost, but some rudiments of the original structure have 
been recognized by Voit (09a, ’09 b) in Lepus, by de Burlet 
(13 b, 718 c, 714 a, ’16) in Cetacea, and by Terry (’17) in the cat. 
The lateral wall of the temporal region shows the same essential 
structure throughout the entire reptilian series, although there 
are striking variations in detail and, in some cases, extreme re- 
duction. In Sphenodon (Schauinsland, ’00; Howes and Swin- 
nerton, ’01) the wall is very solid and has the appearance of a 
fenestrated plate rather than a latticework. Even here the 
majority of the cartilaginous elements and fenestrae of Lacerta 
and Eumeces may be identified. Also in the crocodile (Shino, 
14) the cartilages are -heavy and the fenestrae of restricted ex- 
tent. In the turtles there is extreme variation. Nick (12) 
reports a very complete wall in Dermochelys and a very rudi- 
mentary one in Chelydra; Chelone is intermediate. Emys, 
according to Kunkel (12 b), shows the rudimentary type of 
structure, the taenia marginalis lacking its connections, alike 
with solum supraseptale and with otic capsule. The extreme 
of reduction is reached in the snakes, where the lateral wall is 
practically wanting (Gaupp, ’05 b, ’06; Peyer, ’12). 
5. Fenestrae of temporal subregion 
In figure 33, graphically reconstructed from stages 2 and 5, 
the cartilages of the lateral wall of the temporal region are rep- 
resented, each in its maximum development. If the band of 
questionable cartilage (#), extending from the taenia marginalis 
to the taenia parietalis media, just posterior to the pila acces- 
soria, be ignored, five great fenestrae may be recognized. ‘Two 
of these, the fenestra epioptica (fen.e-op.) and the fenestra prootica 
superior (fen.pr-ot.s.), are in an upper row, dorsal to the taenia 
