SKULL OF THE AGITHOGNATHOUS BIRDS. 291 
well conjoined, all but the short crura. Whilst at the mid line, in front, there is a slight 
carination, towards the side there is some evidence of such a process of absorption as 
would cut off a lateral falciform septo-maxillary. Seen from above (fig. 7, v, 7. al) these 
sides are thick, and form the walls of the scooped bone; they are grafted upon the 
inturned alinasal cartilage. This part of the nasal vestibule is forked, as in the Wren 
(Trans. Linn. Soc. ser. 2, Zool. vol. i. pl. 21. fig. 6), the larger process being above and 
outside, and the lesser below and more mesiad. 
This lower and inner process sends inwards to the septum a crescentic tongue of 
floor-cartilage (n.f); it has a sinuous front and a convex hinder edge. Then the 
main part of the floor, on each side of the septum, is membranous; the septum 
itself (figs. 6 & 7; s.) is not alate. At its extremity the prenasal region has a 
small rod of cartilage (fig. 6, p.m); and the recurrent cartilages appear as the 
triangular median part of a fore belt, which strengthens the floor at this part in a 
manner similar to what is seen behind. Submesially this fore belt sends backwards 
two ears of cartilage, then narrows a little as it passes, on its outer side, into the 
alinasal valve. 
This is unlike any thing I have found in the other Passerines, and well worthy of 
being recorded in figures and in words. The septum nasi (s.z) is thickened where 
the nasal nerves burrow it postero-inferiorly; but in this kind we lose the trabecular 
wings, and, correlated with this deficiency, we find the alinasal cartilages closing in 
below both in front and behind ; the fascia which unites these fore and hind belts 
effectually hides the alinasal turbinal from view. 
In my former paper on this subject (pls. liv. & lxii.) I showed the very remarkable 
conditions of the nasal vestibule in Turnix and Chasmorhynchus as compared with what 
is the typical condition of these parts in the Coracomorphe (e. g. in Corvus and 
Ruticilla) ; here, in Oriolus, we have a third modification for comparison with that 
which is the Passerine exemplar. 
Example 65. Skull of Grey Flycatcher (Muscicapa grisola), 1st summer. 
Family Muscicapide. Group Oscines. 
Habitat. Great Britain. 
In this type also I have been able to show the skuil of a young bird (a fledgeling *) ; 
and I am able to note a very important morphological fact, namely that, whilst in the 
typical Fringillide (e.g. Passer domesticus, Linota cannabina) the moieties of the 
vomer are well coalesced by the middle of incubation, here, in this species, they are 
thoroughly distinct in young birds capable of flight. And this is of the greater con- 
sequence inasmuch as the Muscicapide, like the Chats (Plate LII. fig. 11) and many 
1 This specimen is one, among many, for which I am indebted to Prof. Rupert Jones, F.R.S. 
VoL. x.—Part vi. No. 6.—June 1st. 1878. 2s 
