378 EDWARD PHELPS ALLIS, JR. 
extent the dorsal edge of the mandible. Smith Woodward says 
that there are some traces of an inward palatal extension both of 
the maxillary and the premaxillary, and that there are paired 
vomers, each of which bears a formidable tooth. 
Aside from these very general description of these fishes, I 
only have at my disposal Huxley’s descriptions of Glyptolaemus 
kinnairdi, and Traquair’s descriptions of Tristichopterus, the 
one belonging to the family Osteolepidae and the other to the 
family Rhizodontidae. 
In Glyptolaemus, called by Smith Woodward Glyptopomus, 
the maxillary is not particularly described by Huxley (’61), but 
he shows it, in one of his figures, lying along the lateral edge of 
the anterior end of the palatosuspensorium and overlapped ex- 
ternally by a large tooth-like structure which apparently either 
issues from beneath the suborbital bones, or has its origin on the 
pa’atosuspensorium. If this be the ‘very strong tooth’ mentioned 
by him in the text, and there said to be implanted on the anterior 
portion of the palatosuspensorium, it must be greatly displaced 
in the fossil. It somewhat strikingly resembles, in general posi- 
tion and appearance, the labial cartilage of Polypterus, and if it 
be that labial, here ossified, as it is in Macropoma, the maxillary 
of this fish cannot be an holostean one. The maxillary is, how- 
ever, shown strongly tuberculated in restored figures of certain 
of these fishes, particularly so in Osteolepis, and if it was a super- 
ficial bone, as this would indicate, it cannot be the homologue of 
the bone of Polypterus. 
In Tristichopterus, the maxillary is said by Traquair (’75) to 
be a long and narrow bone, the oral edge of which is distinct in 
the fossil, but the dorsal edge not. Internally, along its anterior 
two-thirds, it is said to be certainly very firmly united to the 
outer margin of the palatoquadrate arch, an interval being left 
posteriorly for the passage of the muscles of the lower jaw. 
The bone is shown, in a restored figure, in contact with the _ 
suborbital and preopercular bones, and slightly overlapping ex- 
ternally the dorsal edge of the mandible. The palatosuspen- 
sorium is shown extending forward approximately to the an- 
terior end of the maxillary, and its posterior border, which 
