PROF. W. K. PARKER ON ®GITHOGNATHOUS BIRDS. 321 
between the septum and perpendicular ethmoid is very small above: it agrees, then, in 
this respect, with Dendrocolaptes. 
The vomer (figs. 4 & 5, v) is very large, relatively ; and anteriorly it is twice as wide as 
it is behind: this answers to Dendrocolaptes. Here the vomers proper do not unite 
with the inturned alinasal lamina (7. a. 2), but form the ossified and coalesced hinder 
portion of the “ vomerine cartilages” (v. ¢), which are longer, relatively, than in Turnia, 
and reach more than halfway along the sides of the septum nasi towards the recurrent 
lamina (rc. ¢). 
This species and the Common Wren (Troglodytes vulgaris), where the two vomerine 
cartilages coalesce in front, and the Hemipod, are the instances which satisfy me that 
the vomerine cartilages are not merely the long extremities of the recurrent fold, 
detached, and separately chondrified, through the rapidly produced ‘ prognathism” of 
the bird’s face, but are a pair of upper labials. The broad shoulders of the vomer 
are formed by the addition of a square septo-maxillary (s.ma) on each side; and it is 
this bone which grafts itself on the inturned alinasal wall (7. a. /). 
The pterygo-palatine arch is very similar to what Iam about to describe in Synallavis 
and Muscisavicola (Pl. LIX. figs. 6 & 9). The pterygoid retains its distinctness (fig. 4, 
py); and its “ hamular process” is long and slender. As in Muscisavicola (fig. 9) and 
Dendrocolaptes (fig. 1), the postpalatine ridges (pt.pa) are fined off; and as in Synal- 
laxis (fig. 6), the slenderer transpalatine spurs (f.pa@) are turned outwards as well as 
backwards. Of the lamine that form the roof and the floor of the nasal passage, the 
latter ends in a long interpalatine spur, and the former is arched (fig. 4, i.pa, e.pa). 
The forward continuation of the palatines is very slender (pr.pa). 
The lateral ethmoids are large, square, and have one wide, large opening above the 
antorbital, for the 1st and 5th nerves. The frontal region of the lateral ethmoid is 
moderate, the os uncinatum below not distinct; and there isno lacrymal, as far as I can 
see; the maxillo-palatines are not pedunculated (see fig. 4, ma.p, which shows the root 
of this process). 
Example 12. Synallaxis flaviqularis. 
Habitat. Chili. Section “ Tracheophone,” Miiller; family “‘ Dendrocolaptide.” 
The skull of this bird is unrivalled for elegance and delicacy of structure; this is 
especially seen in the palate (Pl. LIX. fig. 6). The swollen, cellular basitemporal plate 
(0.4) is bat-shaped, and has the median part not much produced forwards. ‘The para- 
sphenoidal beam (pa.s) is very broad-based, and is without basipterygoid processes. 
From the Eustachian opening (ew) to the solid part of the premaxillaries, the basi- 
facial axis is one continuous structure; but the posterior or upper third of the trabe- 
cular bar is separated from the ethmo-presphenoidal bar by a very large interorbital 
fenestra; the rest of this coalesced arch is in a state of permanent fusion with the 
descending septal crest of the nasal organs. 
VOL. IX.—PART v. December, 1875. 2 
