38 MR. W. P. PYCRAFT ON THE [May 2, 
broad limbs indistinguishably welded with the palatines, agreeing 
in this with Calyptomena and Cymbirhynchus. 
The palatine (Pl. LI. fig. 2a) in Calyptomena is a long bone: 
anteriorly rod-shaped, it extends backwards as far as the 
under surface of the antorbital plate, when, after sending out- 
wards a prominent, rounded elbow—“ transverse bone ”-—it turns 
abruptly inwards, ultimately forming a roughly spatulate plate, 
bent upon itself so as to form a long linear surface running along 
the parasphenoid rostrum, and fusing mesiad with the vomer and 
a free downwardly hanging curtain to form a cavernous space in 
the roof of which is the base of the vomer. 
The palatine of Chasmorhynchus differs from that of Calypto- 
mena in the greater width of the hinder laminated portion and the 
more extensive development of the inferior free edge, forming the 
cavernous space beneath the vomer. This edge now appears 
rather as a shelf-like projection developed from the inner border 
of the shaft of the palatine. 
In Cymbirhynchus the palatine shaft is broader than in 
Calyptomena, and this increased breadth is especially noticeable 
at its junction with the body of the premaxilla. The latter, as 
has already been pointed out, is much more conspicuous than in 
Calyptomena and terminates in a doubly crescentic free edge 
synchronously with the palatines. Thus a relatively enormous 
oblong space is enclosed. In Corydon these features are still 
more exaggerated, the “‘ elbow” is also more strongly marked. 
In broadness and the truncated form of the shaft of the 
palatines, the more specialised Kurylemide recall the Podargide, 
wherein the body of the premaxilla is still more developed and the 
truncation of the palatine distally more marked. Both in the 
specialised Hurylemide and the Podargide the truncation of the 
vomer appears to have been brought about to facilitate the move- 
ments of the nasal hinge, which in both types les immediately 
above the anterior ends of the palatines, while in the more 
generalised Calyptomena, which lacks a nasal hinge, the palatines 
run far forwards. 
The pterygoid in Calyptomena (PI. II. fig. 2a) is a long, 
slender, rod-shaped bone, laterally compressed, and perforated by 
a pneumatic foramen at its articulation with the quadrate. At 
its anterior end it meets its fellow of the opposite side in the 
middle line; and immediately sends upwards and forwards a sub- 
crescentic plate which, embracing the parasphenoidal rostrum by its 
plane surface, affords attachment along its inferior border to the 
vomer. Late in life the articulation with the vomer is succeeded 
by anchylosis. Certain points concerning the morphology of the 
end of the pterygoid will be discussed in the section dealing with 
the nestling skull (p. 43). 
In Chasmorhynchus the anterior ends of the pterygoids do 
not meet in the middle line but impinge instead directly against 
the parasphenoidal rostrum, forming therewith a pedate articu- 
lation, which is largely augmented by “ hemipterygoid” elements 
