262 MR. W. P. PYCRAFT ON THE [Mar. 17, 
forwards into a more or less well-developed spine, the processus 
zygomaticus squamost. The base of this angle serves for the 
articulation of the squamosal head of the quadrate. This zygo- 
matic process is especially well-developed in Cuculus, Crotophaga, 
and Geococeyxz. It is small in Guira and Coua, for example, 
and in the Musophagi. The processus articularis squamosi is 
wanting. 
The temporal fossxe are never very deep, but they may extend 
inwards to within a short distance of the middle line. The 
variations in the extent of these fosse have already been dealt 
with (supra, p. 260). 
The trigeminal foramen in the Cuculi lies immediately above 
the mouth of the anterior tympanic recess, on a level with, and in 
front of, the otic articular surface for the quadrate. In 7uracus 
this foramen is divided by a median vertical bar of bone. 
The orbito-nasal foramen (v') appears to be definite only in 
Geococcyx. inother Cuculine and Musophagine the alisphenoidal 
wall only partially ossifies, and consequently this and other 
foramina around the optic foramen disappear in the dried skull. 
The orbits are large, and roofed by moderately broad over- 
hanging ledges formed by the frontals, and to a slight extent by 
the lachrymals. The orbito-sphenoid does not ossify. 
The interorbiial septum in the Cuculi is generally pierced by a 
large fenestra, which attains its maximum in Dromococcyx and 
Centropus. In © rotophaga, Coua, Piaya, Rhamphococcyx, Rhino- 
coccyx, Khopodytes, and Zanclostomus, however, the fenestra is 
greatly reduced. 
In the Musophagi the fenestra is large in Twracus, small in 
Schizorhis. I have not had an opportunity of examining other 
genera. 
The orbit is bounded in front by the antorbital plate (p. 263). 
The lachrymal in the Cuculi is moderately large, with subequal 
supraorbital and descending processes. The form of this bone 
and its relation to the frontal and nasal bones vary considerably 
however. In RLhamphococeyx calorhynchus only, apparently, is it 
attached merely to the nasals. The orbital process looks entirely 
forwards, instead of upwards: that is to say, it forms a shield 
for the front of the eye instead of an overhanging ledge therefor ; 
the descending process is slender. The frontals rest on the inner 
angles of the orbital process of the lachrymal on either side, and 
appear, in the adult skull, to be cut off from the nasals and pre- 
maxillary process by a sharply-defined groove, which runs across 
the skull from the hinder edge of the orbital process up the 
lachrymal on the one side to that of the other, and simulates a 
nasal hinge. Ahinococcyx curvirostris apparently closely resembles 
Rhamphococeyx, but the lachrymal being completely fused with 
the nasals and the frontal behind it, the precise relations of the 
various regions cannot be made out. 
In other Cuckoos, though exhibiting a distinct tendency to 
form an anterior shield rather than a pent-house ledge, the 
