270 MR. W. P. PYCRAFT ON THE [Mar. 17, 
to the vertical face of the posterior division of the neognathine 
mesethmoid, that is, exactly in front of the antorbital plate of the 
adult. To make the fissure complete, the incision would have to be 
continued downwards so as to completely bisect the plate, whilst 
the rostrum would have to terminate at the free edge of the 
posterior segment of the plate. In the adult skulls the incipient 
fissure remains, placing the right and left olfactory chambers, in 
the dried skull, in communication. The formation of a complete 
eranio-facial fissure is correlated with, and perhaps consequent on, 
the reduction in the length of the parasphenoidal rostrum, which 
in all the Paleognathe is of great length. In a skull of a half- 
grown Casuarius salvadorii it is, however, relatively much shorter 
than in an adult C. australis, and much overhung by the mes- 
ethmoid. Whether this peculiarity obtains also in the adult of 
this species I am unable to say. 
The olfactory cavities do not extend backwards in the Cuculi 
or Musophagi, so as to lie on either side of the mesethmoid, as in 
the Tubinares for example; the antorbital plate arising in the plane 
of the cranio-facial fissure. 
The guadrate does not differ materially from that of the adult. 
The articulare is still distinct. 
b. The Membrane-bones. 
The parietal is oblong in shape, its anterior and posterior 
borders sinuously curved, its mesial border straight, and its 
external lateral border being slightly convex. It is bounded in 
front by the parietal, behind by the supraoccipital, and laterally 
by the squamosal. 
The frontal has its hinder border simuously curved, and 
throughout the greater part of its length applied to the parietal. 
Its postero-external is closely applied to, and ultimately fuses 
with, the supero-anterior angle of the squamosal and the post- 
orbital process of the alisphenoid. In the supraorbital region it 
turns downwards and inwards to form a broad overlapping plate 
articulating with the alisphenoid. From the mid-orbital region 
onward it becomes band-shaped, ultimately being produced into 
an outwardly directed and blunt angle underlying the nasal. 
The squamosal is roughly quadrate in form, and has the superior 
anterior angle produced into a linguiform process which overlaps 
the parietal and alisphenoid. Its antero-ventral angle is produced 
into a small squamosal prominence, the under surface of which 
affords the articular surface for the squamosal head of the quadrate. 
The postero-ventral angle is obliquely truncated, and forms the 
anterior segment of the rim of the tympanic cavity. The supero- 
posterior angle is produced into a shght point which is wedged 
in between the parietal and lateral occipital. The hinder border 
of the squamosal serves to cover in the recessws tympanicus 
superior, which is formed by the absorption of the diploé of the 
lateral occipital. 
