172 
GENEBAL ORNITHOLOGY. 
other cranial characters of these birds is to be noted the articulation of the palate bones with 
the upper beak, like that of the zygoma. The multifarious Picarian birds, or non-passerine 
Insessores, are desmognathous, excepting the schizognathous trogons {Trogonidce) and the 
' ^ saurognathous " woodpeckers. Parker has established the following categories of desmo- 
gnathism : (a) Perfect direct, the maxillo- palatines uniting below at the mid-line ; either with 
the nasal septum free from such bony bridge, as in a duck; or anchylosed therewith, as in many 
birds of prey, (h) Perfect indirect, very common, as in eagles, vultures, owls ) maxillo- 
palatines separated from each other by a cliiuk, but an- 
chylosed with nasal septum. (c) Imperfectly direct; 
maxiUo-palatines sutured together, but not anchylosed. 
'^In young falcons and hawks the palate is at first in- 
direct, is then imperfectly direct, and at last perfectly 
direct." (d) Imperfectly indirect ; maxiUo-palatines 
closely articulated with, and separated by, the median 
septo - maxillary but there is no anchylosis. (e) 
Double : the palatines united as well as the maxillo- 
palatines ; as in the pelican and cormorant above noted, 
in certain Caprimulgine birds, horn-bills, etc. (/) Coin- 
pound : when the properly cegithognathous skull of a 
passerine bird becomes also desmognathous. 
^githognathism (Gr. alyi6a\6s, aigithalos, some 
small bird) is exhibited almost unexceptionally by the 
great group of Passerine birds ; it is also nearly coinci- 
dent with Passeres, though a few other birds, notably 
the swifts (Cypselid(s) , also exhibit it. Huxley's term 
CoracomorpJice, nearly synonymous with Passeres, relates 
to the palatal structure exhibited by a raven (fig. 79), as 
typical of that of Passeres at large. The vomer is a 
broad bone, truncate in front and deeply cleft behind, 
embracing the sphenoidal rostrum in its forks. The 
palatines have produced postero- external angles. The 
maxiUo-palatines are slender at their origin, extending 
inwards and backwards over the palatines and under the 
vomer, where they end free, being united neither with 
each other nor with the vomer. This disconnection of 
the maxiUo-palatines is quoad hoc schizognathous," of 
course ; but such condition, in association with the pecu- 
Uarities of the vomer, is segithognathous. The nasal 
septum in front of the vomer is often ossified in segitho- 
gnathism, and the interval between it and the premax- 
iUse filled up with spongy bone; but no union takes 
place between this ossification and the vomer (Huxley). 
According to Parker, the distinguishing character of the 
iBgithognathous type is the union of the vomer with the alinasal waU and turbinals. He dis- 
tinguishes four styles : {a) Incomplete; very curiously exhibited by the low Turnix, which 
stands near the gallinaceous birds. (6, c) Complete, as represented under two varieties, one 
typified by the crow, an Oscine Passerine, the other by the Clamatorial Passerines Pachrjrham- 
phus and Pipra. {d) Compound, i. e., mixed with a kind of desmognathism, as noted above. 
''Vomer truncated in front" is the general expression for the condition of that bone in the 
Fig. 79. — ^githognathous skull of 
raven, Corvus corax, nat. size, from na- 
ture, by Dr. R. W. Shufeldt, U. S. A. 
Letters as before. N. B. The reference 
line, V, goes to the ossified nasal septum 
borne upon the end of the vomer, which 
latter bone begins at the thickest part of 
the central projection. Mxp underlies V 
and overlies PI, but touches neither. 
