No.3.] CHEEK AND SNOUT OF AMIA CALVA. 449 
The anterior palatal articulation of Amia thus seems to be want- 
ing in Polypterus. There is, however, another, more anterior 
connection, rather than articulation, of the palato-quadrate with 
the skull. It is effected through the intermediation of a bone 
considered by Traquair as the homologue of the vomer both of 
Amphibia and of fishes. This so-called vomer bone, of which 
there are two in Polypterus, one on each side of the head, lies 
“in contact above with the median ethmoid, with the pre- 
maxillary, and with the cartilaginous floor of the nasal cham- 
ber; by the greater part of its outer edge it articulates by 
suture with the maxillary bone, while its posterior extremity is 
articulated with the ectopterygoid, coming also into close con- 
tiguity with the palate-bone and prefrontal.’’ The bone is said 
by Traquair to have been considered by Agassiz as a part of 
the superior maxillary, and by Miiller as a part of the palate 
bone. It certainly seems to be the piscine dermo-palatine 
rather than the vomer, and I shall refer to it again in treating 
of the latter bone. 
It may here be stated that the bone identified by Traquair 
as the palatine of Polypterus was apparently described before 
him by Erdl, and considered by Erdl as the probable homo- 
logue of the anterior “Gaumenbein”’ of the carp (No. 13, 
Pp. 244). 
The septomaxillary element of the skull of ganoids and tele- 
osts thus seems to be developed in connection with an anterior 
ethmoidal articulation of the palato-quadrate with a ventro- 
lateral portion of the chondrocranium. Moreover, both in 
Amia and in Esox, the only fishes so far described in which the 
articular surface of the bone is found uncapped by cartilage — 
that is, as an ossification extending into the cartilage from the 
articular surface with which it is associated — it is found asso- 
ciated with a strictly dermal ethmoid, and not with a primary 
one. This would seem to indicate that it may have its homo- 
logue in some part of the primary ethmoid bone of those fishes 
in which that bone is found, and hence, according to generally 
accepted views, in the vertical plate of the ethmoid bone of 
man. The relations of the two septomaxillary bones of Amia 
to adjacent bones of the region suggest, however, that they 
