1903. ] OSTEOLOGY OF THE CUCULIFORMES. 267 
In all the Cuculi, the palatines meet one another in the middle 
line immediately beneath the parasphenoidal rostrum, which they 
asp laterally through their fusion with the hemipterygoids. 
In the Musophagi the palatines are relatively longer than in 
the Cuculi, from which they also differ in that they taper, instead 
of broaden, rapidly as they approach the pterygoids. Furthermore, 
they do not meet below the parasphenoidal rostrum, but, on the 
contrary, are separated one from another by the whole width of this 
rostrum (Pl. XXII. fig. 2). The dorsal surface of the pterygoid 
end sends up a long and deep, incurved keel, the antero-internal 
angles of which fuse with the vestigial vomer. 
The pterygoids, in the Cuculi, are moderately long and straight, 
and in some, e. g. Crotophaga, Rhinococeyx, Gwira, Taccocoua, 
have the dorsal border raised up into a high, sharp crest, the 
palatine end of which embraces the parasphenoidal rostrum, whilst 
in Eudynamys, Coua, Geococeyx, and Piaya, tor example, this 
crest is absent. The palato-pterygoid articulation is in the form 
of an obliquely transverse hinge-joint, permitting only a lateral 
motion. Basipterygoid facets are absent. 
The hemipterygoid element of the pterygoid is conspicuous only 
in Taccocoua and Geococcyx. Herein it forms a continuation of 
the dorsal crest of the shaft of the pterygoid, and rests on the 
palatine at a slight angle. Secondary fusion between the hemi- 
pterygoid and the main shaft of the pterygoid would reproduce 
exactly the conditions of the palato-pterygoid articulation which 
obtain in the Bucconide and Momotide. 
In the Musophagi the pterygoids are relatively short, somewhat 
twisted, rods, bearing vestiges of basipterygoid facets. They 
articulate with the palatines as in the Cuculi. 
The Mandibles. 
The mandible in the Cuculi has a short, blunt angular process, 
and a moderately long internal angular process. 
In Eudynamys, Cuculus, and Guira the vami are pierced by a 
long lateral vacuity, which is partly closed by a long and slender 
coronoid. In Coua the coronoid terminates midway across this 
vacuity; whilst in Zaccocowa and Centropus this vacuity is quite 
open, the coronoid forming its ventral border. In Piaya, Rhino- 
coccyx, and Rhamphococcyx the vamal vacuity is absent. In 
Geocoecyx it is partly closed anteriorly by the hinder end of the 
splenial. 
The mandible of Cuculus possesses one conspicuous feature in 
the presence of a triangular flange of bone formed by the deflection 
of the superior border of the ramus at the point corresponding, 
in the living bird, to the gape, in the skeleton to the region 
immediately behind the lachrymo-nasal fossa. The flange, 
especially conspicuous in Cuculus canorus, is also fairly distinct m 
Cacomantis, and is traceable in Piaya and Rhamphococeyx. The 
internal angular process is well marked in all the Cuckoos, but is 
especially so in Coua and Centropus. 
