368 EDWARD PHELPS ALLIS, JR. 
vomers of Amia. In any event, Sagemehl’s suggestion (’83, 
p. 187), that the vomer bone of fishes might have been primarily 
the most anterior one of the investing bones of the palatine arch, 
is quite certainly true in so far as the teeth on the vomers of 
Amia are concerned. 
LEPIDOSTEUS 
In Lepidosteus there is a small labial fold, similar to that in 
Amia, and it encloses an holostean maxillary bone which Parker 
(82) refers to as the edentulous mystaceum of an Acanthopter- 
ous Teleostean. That part of this bone that lies in the labial 
fold is, as Parker states, edentulous, but in both 40-mm. and 
80-mm. specimens that I have examined in serial transverse 
sections, I find two or more teeth related to an anterior portion 
of the bone that extends anteriorly beyond the root of the labial 
fold. These teeth lie in the line prolonged of a series of teeth 
that are implanted upon those laterosensory canal bones that 
Parker refers to as the maxillary chain, but the holostean maxil- 
lary is not, as Parker states, one of that chain of bones, for its 
anterior end lies definitely ventral to them, and ventral to the 
line prolonged of the supralabial furrow, while the canal bones lie 
dorsal to that line prolonged, and hence, as they normally 
should, in the line of an anterior prolongation of the supralabial 
fold. The teeth that are implanted upon these canal bones were, 
however, quite certainly not developed in relation to the supra- 
labial fold, for the posterior ones pierce the ectoderm ventral 
to the anterior end of that fold. These teeth are, as above 
stated, implanted upon the canal bones, and they form the row 
of small sharp teeth said by Parker (l.c., p. 478) to be implanted 
along the outer edges of those bones of the adult. Internal to 
these teeth there is, in my embryos, a row of teeth that are not 
implanted upon any bone whatever, their bases not reaching 
the overlying portions of the canal bones. In the adult most 
of these teeth are firmly implanted upon those bones, some 
of them, however, still remaining unattached, and, being held 
only by the surrounding tissues, are loose and movable. They 
form the row of large sharp teeth said by Parker to lie in the 
