268 MR, W. P. PYCRAFT ON THE [ Mar. 17, 
In the Musophagi the angular is sharply truncated posteriorly, 
and the internal angular process is short and blunt. 
In Schizorhis the ramal vacuity is closed posteriorly, in Twuracus 
it is closed completely, by the coronoid. 
The Hyoid. 
Unfortunately the hyoid bones have been preserved only in one 
or two of the skeletons of this group in the Museum Collection. 
Years ago, when these skeletons were made, according to the 
prevailing custom, the hyoid bones were not regarded as of value. 
In Seythrops the basihyal is slender and rod-shaped ; the Ist 
‘basibranchial triangular, with concave sides, the 2nd of medium 
length, styliform and tapering. The ceratobranchial and epi- 
branchial are subequal in length and offer no points for special 
comment. 
In the Musophagi the basihyal bones are reduced to mere 
vestiges. The lst and 2nd basibranchials are short and fused. 
The ceratobranchials are only slightly longer than the epi- 
branchials. 
ii. THe SKULL OF THE NESTLING. 
The National Collection of nestling skulls of this group is 
extremely limited, containing only one skull of Cuculus canorus 
and one of Greococcyx californianus. A series of skulls of nestlings 
and of immature individuals of various species of Cuckoos, as 
well as of Plantain-eaters, would be a useful addition to the 
Collection. At present the latter contains no skeletons of nestling 
Plantain-eaters and few skeletons of adults. 
a. Cartilage-bones. 
The basioccipital is somewhat linguiform in shape, and widens 
gradually from behind forwards. It is bounded on either side by 
the lateral occipitals, in front by the basitemporal plate. Its 
posterior border forms the greater portion of the occipital condyle. 
The exoceipital, or lateral occipital, viewed externally, takes the 
form of a broad horizontal plate bounding the basioccipital on 
either side, and extending backwards and outwards, expands into 
a fan-shaped plate, the superior half of which is wedged in 
between the supraoccipital, parietal, and squamosal, whilst the 
ventral, or downwardly directed, moiety forms the posterior 
boundary of the tympanic cavity. The lateral segment of the 
foramen magnum is formed by the horizontal plate of the lateral 
occipital, which also, by the way, forms the extreme outer angle 
of the occipital condyle. The fact that the exoccipital comes into 
contact with the parietal is noteworthy: a similar relationship 
obtains also in Dromeus among the Paleognathe, and will 
doubtless be found among several other Neognathine forms. The 
exoccipital is only just visible, from the cranial cavity being 
overlaid by the opisthotic. 
