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fibrous band that is said to be prespiracular in position and to bear 
the spiracular cartilage. But as Rıpzwoon (1895) has since shown 
that this so-called prespiracular ligament is in reality a postspiracular 
one, it certainly can not represent the dorsal end of the mandibular 
arch. SEWERTZOFF (1899), from his work on embryos of Acanthias 
and Pristiurus, agrees with Huxuey that the orbital (palato-basal) 
process represents the dorsal end of the mandibular arch, but he makes 
no comparison of the process with parts of the amphibian palato- 
quadrate. Gaupp (1906, p. 703) agrees with Huxıey that the pedicle 
(processus basalis) of amphibians “appears” to correspond to the 
orbital (palato-basal) process of selachians. Van WısHE (1882) says 
that the otic process of Amia apparently represents the true dorsal 
end of the mandibular arch, and further suggests that the process may 
possibly represent the ascending process (‘‘Proc. adscendens’’). 
And as one further interpretation of the parts here concerned it may 
be said that PoLLAarn (1894) considered that the so-called otic process 
of Heptanchus contained the homologue of the hyomandibular of 
teleosts. 
With these several conclusions my work, as already stated, 
is not at all in accord, and I look for the homologue of the pedicle, 
or processus basalis, of amphibians in that low and rounded ridge on 
the dorsal edge of the palato-quadrate that, in Chlamydoselachus, 
forms the mesial edge of the groove that gives insertion to the M. le- 
vator maxillae superioris. This part of the palato-quadrate of Chlamydo- 
selachus approaches somewhat closely the lateral wall of the otic 
capsule, and in Cestracion it is shown by Huxury (1876) as apparently 
there being in extensive contact with the neurocranium; HuxLEy 
even saying, in his index lettering, that a certain point of this part 
of the palato-quadrate of Cestracion “answers to the pedicle of the 
suspensorium in Amphibia.” The ramus palatinus facialis runs down- 
ward dorso-anterior to the processus basalis in amphibians, while it 
runs forward postero-ventral to the orbital process in selachians, 
which latter process thus can not be the homologue of the processus 
basalis if the relations of the nerve to the two processes are of any 
morphological importance. 
In urodeles the processus basalis fuses with the cranial wall 
in the otic region (GAupr, 1906). In anurans the process articulates 
with the cranial wall in the same region (GauppP, 1906); but the anlage 
of the process is here said by GAupp (1893, p. 443) to be developed, 
