SKULL OF THE £ZGITHOGNATHOUS BIRDS. 283 
is similar to that of Suthora; but the right and left keels come nearer together, leaving 
a narrow postnarial passage; they have not so steep a posterior edge, which is gently 
concave or emarginate: the difference here is very slight between the lesser and larger 
skulls. The transpalatine region (¢.pa) is equally steep and strong; the snags them- 
selves are more dilated and round at the end. 
The ethmopalatal lamina (figs. 5 & 6, e.pa) is of greater extent than the interpala- 
tine (ipa), and not merely equal as in Suthora and Parus; it ascends very high, and 
is a large half-coil, as in many of the Passerines of South America. The interpalatine 
snags are thick and spongy. The prepalatine bar (pr.pa) is large and lathy, wider 
behind than it seems from below, because twisted on itself ; at the middle, as in 
Suthora, it widens sensibly, and then narrows a little towards the fore end, so as to 
expose the alinasal turbinals (a. td) ; it is completely ankylosed to the rostrum. Thus 
the palatines differ more in “letter” than in “ spirit” from those of Swthora, and not 
otherwise than the rest of the skull differs. 
The cranio-facial hinge exists here only in virtue of the elasticity of the bones; 
for the nasals and nasal processes of the pramaxillaries pass, by ankylosis, directly 
into the frontals; and the maxillaries, laterally, pass insensibly into the rostrum (ma, 
d.px). Thus we miss that parrot-like mobility of the face, and are, consequently, on 
the outer border of the Tit family. The fore part of the roof of the rostrum is deeply 
grooved in a rounded manner; and this groove ends in a triangular tongue of bone as 
in Parus ; the“ recurrent” processes are not distinct from this flap. 
Whilst in Parus the palatal processes of the pramaxillaries are almost absorbed (fig. 1, 
p-px), in Cyclorhis as in Suthora they have lost all their distinctness, both from the 
dentary edge and from the prepalatine bar (fig. 5, p. pa, d.pa, pr.pa). The maxil- 
lary widens as it passes into the jugal bar (j), which is of moderate strength. The 
maxillopalatine processes (mv.p) have a short, straight, flat pedicle, which is as broad 
at its root as at the dilated end. That end is swollen, pneumatic, and just like that 
of a Tit. 
The vomer (v) is large; but its crara converge, and are completely ankylosed to the 
shelly ethmo-palatines. The emargination in front is wider and straighter than in 
Suthora, and its crura somewhat shorter; but they are extremely alike. The “ horns” 
of the vomer pass insensibly, by bony substance, into the large alinasal turbinals, 
which are well ossified and, as in Suthora, show through the short round nostril (figs. 
5 & 6, a.tb). As in Suthora, the septomaxillaries do not keep distinct. The septum 
nasi (fig. 5, s.m) is a very remarkable mass of cavernous bone; it is completely ossified, 
not merely calcified; and the nerve-bridges are seen as the side-walls of a large air- 
cavity, which runs forwards along the mid line, above the lower face of the alinasal 
turbinals. Looking through the chink between these scrolls we can see that the whole 
septum is hollowed from below, the ossified trabecular flaps forming the shelving roof 
of the long air-chamber. 
VOL. X.—PaRT vi. No. 5.—June 1st, 1878. 2R 
