No. 3.] CHEEK AND SNOUT OF AMIA CALVA. 457 
component, a supposition which, according to Gaupp, is incor- 
rect (No. 17, p.-82); 
Between the anterior ends of the so-called vomers of Polyp- 
terus, Pollard found and described, as already stated, a small, 
median, impair bone, which he was at first inclined to consider 
as the vomer, though it is said not to be the homologue of the 
two so-called vomer bones of Amphibia, which he identified as 
the dermo-palatine. Later he concludes that this impair bone 
is a new bone “which only doubtfully reappears again in the 
animal kingdom,” and he accordingly gives it a new name, 
calling it the dermal subrostral. As already stated, I consider 
this median, subrostral bone of Pollard as the probable homo- 
logue of the vomers of Amia fused with each other, and I am 
inclined to think that the single, separate bone of Pollard’s 
specimen is found in Traquair’s specimen, which was possibly 
a different variety of Polypterus, as two separate parts, each 
of which is fused with the premaxillary of its own side of the 
head. 
If this be so, the so-called vomers of Polypterus must neces- 
sarily be the homologues of the palatine bones of other fishes, 
as Miiller is said:to have asserted, or of the dermo-palatines, as 
Pollard (No. 30, p. 412) has suggested. I consider them the 
homologues of the dermo-palatines, a conclusion which entails, 
according to Pollard, the further conclusion that the two vomer 
bones of urodeles and the single vomer bone of mammals are 
the homologues of the dermo-palatines of fishes, and not of the 
vomer bone or bones. This conclusion, in so far as it relates 
to urodeles and other amphibians, I fully accept. 
According to Sutton (No. 42), the so-called vomer bone or 
bones of fishes and amphibians are represented in man and 
mammals by the prepalatine part of the hard palate, that part 
of the palate ossifying from a distinct and separate center of 
the superior maxillary bone. This statement presupposes the 
homology of the vomer bones of fishes and amphibians, which, 
as stated above, I am strongly inclined to doubt. It seems to 
me much more probable that the so-called vomer bones of 
Polypterus and Amphibia are represented in the horizontal 
plate of the palate bone of man and mammals, and not in the 
