AND DEVELOPMENT OF THE BIRD'S SKULL. Ill 



" Coracomorphse ;" spiny rudiments, however, are not seldom seen, especially in southern 

 forms, as, for instance, Gymnorhina, Eomorus, Dendrocolaptes, but most clearly of all 

 in a form allied to the Sun-birds, namely Anthreptes malaccensis. 



I have purposely mentioned these modifications of the face in the very numerous types 

 of the Crow form, and if it had been possible I should have sought to make the " iEgi- 

 thognathse" run parallel with the " Coracomorphse ;" but Nature herself forbids this. 

 Yet it is some gain to have been able, as Professor Huxley has done, to take in a lump 

 nearly half of the myriad of known birds, to show that all these are " iEgithognathous," 

 and to call them by the name of the commonest and yet one of the highest of the group, 

 namely, the Crow. Here the zoological group cannot be made to hold all the mor- 

 phologically agreeing types, the " symmorphs." This will be felt still more strongly in 

 the next group to be considered, the " Coccygomorphse " (Huxley, op. cit. p. 466), 

 which, with an extension of its boundaries to be proposed here, will contain " iEgi- 

 thognathse," " Schizognathse," and " Desmognathse." 



To make the matter a little clearer, it is necessary to show that there are several 

 varieties or degrees in the morphological types of the ornithic palate, as designated by 

 Professor Huxley. In the " iEgithognathous " palate I find three varieties, namely : — 



a. Incomplete. 



o. Complete : var. 1. 



c. Complete : var. 2. 



d. Compound. 



a. Incomplete " iEgithognathism " occurs in the " Turnicimorphs," Hemipodius or 

 Turnix. Here the vomerine cartilages are very large and incompletely ossified, and the 

 broad double vomer has a septo-maxillary at each angle ; but these bones are only 

 strongly tied to the " alinasal" cartilage, and do not graft themselves upon it. 



b. Complete : var. 1. This occurs in some of the lowest harsh-voiced " Coraco- 

 morphse." The vomers are developed in large " vomerine cartilages," which they often 

 only partially ossify ; but these osseous tracts are distinct from those of the often bony 

 alinasal walls and turbinals : a small septo-maxillary on each side generally appears, 

 limpet-like, on the angle of the alinasal inturned cartilage, but does not run into it. 

 This is well seen in Pachyrhamphus, Pipra, and Thamnophilus. 



c. Complete : var. 2. This occurs in an immense group, comprising most of the 

 " Coracomorphse " and also the Swifts (" Cypselidse ") ; here the vomerine bones are 

 grafted upon the nasal wall, and thus the bird loses its primary schizognathism. 



d. Compound. This type occurs where, in a perfectly segithognathous face, desmo- 

 gnathism is produced by ankylosis of the inner edge of the maxillaries with a highly 

 ossified alinasal wall and nasal septum. — Examples, Gymnorhina tibicen, Paradisea 

 papuana, Artamus leucorhinus. Of this type a feebler form is produced when the 

 maxillaries only coalesce with the ossified alinasal wall, as in Dendrocolaptes albicollis, 

 Thamnophilus doliatus, and Phytotoma rara. 



Por Professor Huxley's account of the Desmognathous palate, I refer to his paper 

 (p. 435). I have one remark to make, namely, that the vomer is very hroad antero- 

 inferiorly (as in the Chelonia) in the most perfectly desmognathous Raptorial palate, 



