AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, JUNE 30. 
THE HOMOLOGIES OF THE MAXILLARY AND 
VOMER BONES OF POLYPTERUS 
EDWARD PHELPS ALLIS, JR. 
Menton, France 
EIGHTEEN FIGURES (THREE PLATES) 
In a work published in 1900, on the maxillary and premaxillary 
bones of Polypterus, I came to the conclusion that those bones 
were each formed by the fusion of two components usually found 
separate and distinct in the Holostei and Teleostei, one of those 
components being developed in relation to the teeth that the 
bone in question bears, and the other in relation to adjacent 
portions of the laterosensory canals. The teeth on the maxillary 
were said to not be the homologues of the maxillary teeth of 
Amia and the Teleostei, and to be, in all probability, dermo- 
palatine ones and the homologues of the maxillary teeth of the 
Mammalia. The so-called vomer was considered to be de- 
veloped in the maxillary breathing-valve of the fish. 
In a later work (Allis, 714), I described in certain of the 
Selachii a fold of the mucous lining of the buccal cavity that 
enclosed the mesial portion of the palatine process of the 
palatoquadrate. This fold had so strikingly the position of the 
maxillary breathing-valve of the Teleostei that I suggested that, 
in the latter fishes, the cartilage enclosed in the fold had been 
resorbed, thus leaving the fold itself as the breathing-valve of 
the fish. The so-called vomers of Polpyterus, considered to have 
been developed in this fold, were then mesial dermopalatines, 
and the maxillary bone a lateral dermopalatine. 
In a still later work (Allis, ’17, ’18), I described the lips and 
labial folds in certain fishes, and came to the conclusion that the 
definitive lips of the Crossopterygii, Holostei, and Teleostei were 
secondary ones that had been developed external to the primary 
lips, and that that part of the buccal cavity that lies between 
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