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necessarily, in the early ancestors of man, excluded from the bounding 
side walls of the cranial cavity proper, as they (the pedicles of the 
alisphenoid) are in Amia. 
The pedicle of the alisphenoid bone i Amia also forms, on either 
side of the head, the anterior portion of the bounding side wall of the 
so-called upper lateral chamber of the myodome, and this chamber 
of Amia, later called by me the trigemino-facialis chamber, was said 
(1897 b, p. 19) to be “both functionally and in position the equivalent, 
if not the homologue, of the cavum Meckelii of man’; a statement 
which should doubtless have been qualified by the addition of the words 
“plus some portion of the canal that transmits the nervus facialis.”’ 
In certain teleosts the parasphenoidal leg of the alisphenoid was shown 
be me (1909) to be largely or wholly represented by membrane only, that 
part of the trigemino-facialis chamber of these fishes that is enclosed 
within the bony walls of the neurocranium thus not being the exact 
equivalent of the chamber in Amia (Aruıs, 1903, p. 94). In Lepidosteus 
the alisphenoid and the trigemino-facialis chamber were shown to be 
as in the teleosts above referred to, while in Cottus the parasphenoidal 
leg of the alisphenoid was shown to be of bone and the external wall 
of the trigemino-facialis chamber, and not the internal one, to be of 
membrane. 
If the homologies above suggested are correct, it is evident that 
the reptilian antipterygoid must be not only the homologue of the 
parasphenoidal leg of the alisphenoid of Amia but also of the corre- 
sponding part of the human ala temporalis. And if Gaupp’s (1900) 
figures of the chondrocranium of Lacerta agilis be considered, it would 
seem practically certain that if the antipterygoid, as there shown, 
should fuse below with the basipterygoid process and above with the 
side wall of the neurocranium, conditions so markedly similar to those 
in Amia would arise that an homology must be assumed. And this 
is also not only Fucus’s (1910 and 1912) recently expressed opinion, 
but is said by that author to have also been the opinion of both RATHKE 
and P. ALgrecHt. Gaupp (1900, p. 546) however says that this anti- 
pterygoid element of the reptilian skull is absent in mammals, and he 
derives the mammalian ala temporalis from the reptilian basipterygoid 
process alone. Furthermore, Gaupp (1905) has given, in Sauropsida and 
Mammalia, to what would seem to be the strict homologue of the trige- 
mino-facialis chamber of my description of fishes, less some portion of 
the pars facialis, the name cavum epiptericum; P. ALBRECHT, according 
