260 MR. W. P. PYCRAFT ON THE | Mar. ilies 
The Cranial Roof.—The cranial roof is never marked by supra- 
orbital grooves. 
The parietal region, in certain genera of Cuculi, is marked by 
deep temporal depressions (temporal “ fossee ”), which may meet in 
the middle line soas to form a faint sagittal crest, e.g. Khopodytes, 
Piaya, Rhinococcyx, and Rhamphococcyx; ov they may be divided 
by a low broad ridge, as in Geococcyx, Taccocoua, Saurothera, 
Eudynamys, Guira, Centropus, and Crotophaga. In Coua, 
Coccystes, Cuculus, and Cacomantis the temporal fossa is either 
barely perceptible or confined entirely to the lateral aspect of the 
cranium. Geococcyx, it should be remarked, presents an inter- 
mediate stage in this character; the width of the ridge dividing 
the right and left fossee being extreme, so much so that they 
barely pass beyond the lateral aspect of the skull. 
The interorbital region is moderately wide in all the Cuculi, 
save in Sawrothera, but even in this genus it is not conspicuously 
narrow. In the middle line the region may be marked with a 
distinct furrow as in Cowa, or even by a low ridge as in Hudynamys. 
The interorbital region is bounded anteriorly by the lachrymals ; 
these do not develop outstanding supraorbital processes, and are 
not conspicuous from this aspect of the skull. There is no trace 
of the fusion of the frontal and nasal bones. 
In the Musophagi the temporal fosse are not strongly marked, 
and are confined to the lateral aspect of the skull. The parietal 
region is more rounded than in the Cuculi; and in Zwracus is 
marked by a median furrow, so that the form of the cerebral 
hemispheres is distinctly indicated. In other respects this region 
of the skull resembles that of the Cuculi. 
The Base of the Skult. 
The basitemporal plate, in the Cuculi, is flattened and triangular 
in shape, and with the apex lying immediately beneath the 
Eustachian apertures. Posteriorly it is bounded by a precondylar 
fossa, which, though generally barely perceptible, in Hudynamys, 
Centropus, and Geococcysx is fairly deep. The lateral angles of the 
base are truncated, and, turning sharply downwards, cross the 
paroccipital notch to form the lower portion of the rim of the 
mouth of the tympaniccavity. In some genera, e. g. Coua, Guira, 
these downwardly-directed angles are very prominent and simulate 
mammillary processes. 
The two sides of this triangular plate have fused with the 
ossified connective tissue forming the anterior wall of the recessus 
tympanicus anterior. Consequently the HKustachian grooves have 
been converted into tubes opening directly above the apex of the 
triangle. 
The parasphenoidal rostrum bears slight vestiges of basi- 
pterygoid processes in Hudynamys only among the Cuculi. 
The rostrum is relatively long, and curves slightly upwards. 
In the Musophagi the basitemporal plate, like that of the 
