878 SK OLL 
fuse with the Premaxillary, Nasals, Palatines and Jugals, frequently 
also with the Vomer and Lacrymals. Each Maxillary is usually 
pyramidal in shape, having an outer, inner and ventral surface, the 
anterior corner of which joins the Premaxilla, the posterior the Jugal, 
and the dorsal the descending process of the Nasal. It varies much 
in size: very small in the Gallinx, it is in the Ardex next to the 
Preemaxilla the most conspicuous bone of the Skull. Inwardly 
each Maxilla sends out a more or less horizontal transverse process, 
the proc. maxillo-palatinus, of which more presently. 
The so-called Palatines are long, and for the most part flat 
and horizontally-placed bones, always fused at their anterior end 
with the Premaxilla, and frequently with the ventral surface of 
Maxille and their maxillo-palatine process, just mentioned, while 
posteriorly they rest movably on the Przesphenoid rostrum, articu- 
lating also, in most Birds, with the anterior end of the Pterygoids. 
The Palatines form the greater portion of the palatal roof of the 
mouth, and border the CHOAN# (p. 87) or inner narial openings. 
The Vomer, a median bone, rests on the Preesphenoidal rostrum, 
and to the ventral view appears between the Palatines. It is very 
variable in shape and size, being wholly absent or reduced to a 
mere trace in the Gallinx, Pteroclidx, Columbx, Psittaci, Musophagidzx, 
Alcedinidx, Todidx, Coliidex, Upupide and Bucerotide, while it is 
small in the Coractide and Meropidx. In Pici it is secondarily re- 
solved into a right and left half, which in Galbulide and Bucconide 
are very much reduced in size.? 
1 On the various bones of the palate, Prof. Huxley based his classification of 
CARINATS, published in 1867 (see INTRODUCTION), dividing them into four 
sub-orders—DROMHOGNATH®H, SCHIZOGNATH®, DESMOGNATH® and ANGITHO- 
GNATHS. As details of the cranial structure have become better known, many ~ 
additions to and corrections of the original scheme have been rendered necessary, 
chiefly through the labours of Parker, Garrod and Forbes, Profs. Magnus and 
Fiirbringer and Dr. Shufeldt. Doubtless the most primitive formation is the 
Schizognathous, whence has arisen the Desmognathous—either by direct 
approach of the Palatines in the middle line, or by the help of the Ethmoid 
and internasal septum. Desmognathism therefore does not necessarily imply 
blood-relationship, but has been reached independently in various groups, while 
a like consideration applies to the Hgithognathous feature, which is also derived 
from earlier Schizognathous conditions. Thinocorys and T'urnix, for instance, 
are incompletely Aigithognathous, and the same may be said of Menura, while 
the Indicatoride and the Cypselidew are as completely Agithognathous as the 
true Passeres, exclusive of the Schizognathous Furnariing. Among certain 
Passeres, such as Gymnorhina, Paradisea, Artamus, Dendrocolaptes, Thamno- 
philus and Phytotoma, what may be called compound Agithognathism prevails, 
in that fusion of the Palatines with each other at their anterior end and with 
the internasal septum leads to a sort of Desmognathous condition. 
According to our present knowledge, the following forms and groups are 
Schizognathous :—Struthio, Apteryx, Crypiuri, Sphenisci, Tubinares, Colymht, 
Podicipedidx, Alcidx, Laridx, Limicolx (excl. Thinocorys above named), Ptero- 
