1905. ] OSTEOLOGY OF THE EURYLEMIDA. 35 
The cerebral fosse are relatively of considerable size, though 
relatively smaller than in Corvus for example. Thus, in the 
Hurylemids the cerebral fossa is only distinguishable from the 
mesencephalic fossa by reason of the boundary-line of the 
tentorial ridge. In Corvus the mesencephalic fossa forms a 
totally distinct basin-shaped cavity, lying as it were within the 
cerebral fossa, which dips down to the outer side and below the 
level of the fossa in question in the form of a deep pocket. 
Menura represents a half-way stage between the Corvide and 
Kurylemidze. In Menura, moreover, the roof of the cerebral 
fossa is marked by a low ridge roughly dividing the fossa into 
two equal parts. 
There is a well-developed bony falx. 
The olfactory fossee are reduced toa pair of small pits. But 
there are strong impressions of an olfactory tube to be found in 
the fore part of the cerebral fossa of the Eurylemide. 
The Premaxilla. 
The premaxilia in the Eurylemide forms the major part of the 
upper half of the beak. Hooked at the tip, and of extreme 
breadth, it recalls in many respects that of many of the Coraciide, 
e. g. Hurystomus, on the one hand, and of some Caprimulgi, 
e. g. Podargus, on the other. When these several types come to 
be compared, however, these resemblances will be found to be but 
slight. 
More significant is the close resemblance to the Cotingide. 
This is well brought out in the skull of Calyptomena, which, as 
will be shown presently, presents many features in common with 
Chasmorhynchus. 'The number of other skeleton characters which 
these two forms possess in common suggest affinity between the 
two groups, rather than homoplasy. 
In Calyptomena, which I propose to take as the typical 
Kurylemid for the purpose of comparison, the body of the pre- 
maxilla is moderately large. The nasal process, fusing with the 
nasals, is sharply truncated caudad, and articulates with the 
frontals by a hinge. In this respect the Kurylemid skull re- 
sembles that of the Podargide, and not of the Coraciide. 
The low position of the skull of Calyptomena is indicated by a 
comparison of the narial aperture with that of the skulls of other 
Eurylemid genera. 
In Calyptomena the nasals are of the typical holorhinal shape 
with an obliquely sloping descending process. The nasal fossa, 
in the dried skull, is a long oval aperture showing, within the 
cavity, a narrow ridge of bone continued from the palatal border 
forwards to meet a low septum hanging from the middle line of 
the nasal process of the premaxilla. The septum represents the 
ossified remains of the septwm nasi; the small plate of bone 
running inwards from the level of the tip of the palatine is a 
portion of the alinasal cartilage which has become ossified. 
3* 
