1898.] OSTEOLOGY OT BIRDS. 93 



plate which unites with its fellow in the middle line of the palate." 

 In other words, the maxillo-palatine process represents the 

 internal palatine border of the maxilla. In some Ducks, and in 

 Geese, these processes are prolonged backwards beyond the fused 

 posterior border so as to embrace the vomer between them. Such 

 backwardly directed processes may be further studied in Arclea, 

 C'ieonia, Accijntres, PhaetJion, and Frerjata (PI. Till. figs. 1 & 4). 



It is on account of these backwardly directed processes that 

 Mr. Beddard has been led to ask, " But can PhaetJion be accurately 

 termed a desmognathous bird?'" Later on he answers it, 

 " Phaethon is really no more desmognathous than is J^climophorvs 

 (a schizognathous bird), if we apply the term as Huxley applied it ; 

 for the maxillo-palatines in both are widely apart, the vomer lying 

 between them." He continues, " In front of the maxillo-palatines, 

 however, in Phaethon the bony palate forms a continuous 

 platform." 



Mr. Beddard's error is, I think, obvious : he has, for the moment, 

 allowed himself to regard the backwardly directed prolongations as 

 if they represented the entire maxillo-palatine process (PI. YIII. 

 fig. 5). The bony palate which " forms a continuous platform " 

 is really formed by the processes in question, whilst the bones 

 so-called in his paper are but parts of the same. 



"When discussing the nature of the palate in SuJa and Phala- 

 crocorax, he writes : — " If we are to apply the term desmognathous 

 to these birds, it must be on the understanding that it is a 

 different kind of thing from the desmognathism of — say — the 

 Anseres." His reasons are the following : — the maxillo-palatines 

 in Phalacrocorax, Plotus, and Sula consist of a " thick mass of 

 bone running upwards towards the roof of the skull. Their 

 direction is quite different from the horizontally disposed maxillo- 

 palatine of Phaethon. The conditions observable in the base of 

 the skull of Fregata appear to me to clear up this somewhat 

 puzzling discrepancy. In Fregaia, we have hoth the horizontal 

 maxillo-palatines of Phaethon, separated from each other in the 

 middle line as in that genus, and the obliquely rvnning ' maxillo- 

 palatines ' of Phalacrocorax. As co- existence undoubtedly disproves 

 homology, it seems to me to follow that true maxillo-palatines, 

 comparable to those of other birds, are wanting in Sula and 

 Phalacrocorax." 



1 feel perfectly certain that if Mr. Beddard had carefully 

 examined the skull of Fregata (PI. A^III. fig. 4) he would have seen 

 that the horizontal maxillo-palatines and the " obliquely running 

 maxillo-palatines " were both parts of one and the same bone ; 

 that the " horizontal maxillo-palatines " were nothing more than 

 backward continuations of the main body of this bone as seen in 

 Arclea, &c. This being so, then the maxillo-palatines of Sula and 

 Phalacrocorax (PI. YIII. fig. 3) differ only in that they are sharply 

 truncated posteriorly — have no " horizontal " processes. In Plotus 

 vestiges of these last yet remain, 



