LIPS AND NASAL APERTURES IN FISHES iW E 
upward between the outer surfaces of the maxillary and pre- 
maxillary and the inner surface of the lachrymal,”’ but I did not 
then recognize that the projecting fold which encloses the ventral 
edge of the lacrimal bone had any morphological significance. It 
is, however, quite unquestionably the homologue of the supra- 
maxillary fold of the Holocephali, the fold in the one being 
related to a latero-sensory line and in the others to an ampullary 
line, for the line of ampullary pores related to this fold in 
Chimaera marks the primitive position of the related ampullary 
sacs (Allis 01). In Amia this fold and furrow are much less 
developed than in Scomber, but they are both still related to the 
lacrimal bone, and the base of the shank of the maxillary bone 
passes upward in the furrow, internal to the fold. In Gadus the 
fold has been extended forward until it meets in the median line 
and is there continuous with its fellow of the opposite side, the 
fold lying internal to the ventral edges of the lacrimal and first 
suborbital bones. The lacrimal bone here extends far forward 
between the upper edge of the mouth and the nasal apertures, 
and is traversed by the buccalis latero-sensory canal. This 
canal does not extend, in this fish, anterior to the lacrimal bone, 
the antorbital and dermal ethmoid bones of Amia, and the 
sections of latero-sensory canal related to them, not being 
found here. The supramaxillary fold is thus related, in both 
Gadus and Amia, to the suborbital portion of the buccalis 
latero-sensory canal and not to its antorbital section, and, as 
this section of the canal in Amia turns upward in the lacrimal 
bone posterior to the posterior nasal aperture, the supramaxillary 
fold also turns upward there, while in Gadus, because of the 
different position of the lacrimal bone, the fold runs forward, 
oral to both nasal apertures. In Ophidium, Merlangus, Ammo- 
dytes and Pleuronectes I find the supramaxillary fold in the same 
position as in Gadus, and also continuous with its fellow of the op- 
posite side, and as I do not find it so in any of the other Teleostei 
at my disposal, this is apparently a characteristic of the Anacan- 
thini. The position of the fold would here seem to be determined 
by the position of the canal, rather than the position of the canal 
by that of the fold. No teeth are ever found, so far as I know, 
JOURNAL OF MORPHOLOGY, VOL. 32, NO. 1 
