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is represented in that transverse ridge of cartilage that forms the hind 
end of the surface by which the palato-quadrate articulates, in the 
one with the ventral surface of the chondrocranium in the ethmoidal 
region (Anus, 1898), and in the others with the lateral arm of the 
ectethmoid. This ridge, in Amia, Scomber and the Mail-Cheeked 
Fishes (Aruıs, 1897 a, 1903 and 1909), gives insertion to a ligament 
which has its origin on the anterior wall of the orbit, the ligament 
holding the palato-quadrate up against the articular edge on the neuro- 
cranium and being the evident homologue of the large capsular liga- 
ment in Chlamydoselachus. 
The otic process of Chlamydoselachus is said by Garman to be 
“formed by a short bend in the thin upper edge”’ of the palato-quadrate. 
GooDEY says that he failed to find this process in his specimens. In 
all my specimens, I find the process at the bend described by Garman, 
but the bend marks the position of the process rather that forming 
it, Goopry’s figure representing the conditions much better than 
GarMan’s. The process is a long low thin ridge of cartilage which 
forms the lateral border of what I consider as simply the thick dorso- 
mesial edge of the palato-quadrate, the mesial border of this edge 
being formed by a still lower, and thick rounded ridge. Between these 
two ridges there is a long narrow and shallow groove which, because 
its lateral border is taller than its mesial one, has the appearance of 
lying on the mesial surface of the cartilage. In this groove the M. 
levator maxillae superioris (FÜRBRINGER, 1905) has its msertion, the 
mesial border of the groove accordingly corresponding to what, follow- 
ing van WisHE (1882, p. 280), I called, in Amia, the anterior process 
(Spitze) of the metapterygoid, and what I have since described in 
Scomber and the Mail-Cheeked Fishes as the mesial flange on the hind 
edge of that bone. In Chlamydoselachus, as in Amia and teleosts, 
the ramus mandibularis trigemini runs outward across the anterior 
edge of the M. levator maxillae superioris and then ventro-posteriorly 
along its external surface, that is morphologically antero-lateral 
to the otic process, while the efferent pseudobranchial artery runs 
upward internal to the levator muscle and hence morphologically 
in the groove that lies between the otic process and the low ridge that 
represents the mesial border of the dorso-mesial edge of the palato- 
quadrate. 
The low ridge just above referred to has never been described, 
so far as I can find, in any selachian, and yet it seems to quite un- 
