1906.] OF THE TRACHEOPHONE PASSERES. 143 



parasphenoidal rostrum and passes over, and beyond, the hinder 

 ends of the palatine for some considerable distance, so that what 

 appears to be the hemipterygoid lies immediately under the pedate 

 expansion of the main shaft of the pterygoid. 



The differences which obtain among these groups in the 

 matter of the palato-pterygoid articulation are of sufficient 

 niterest to demand some further notice. I have shown that the 

 Piprifh-e, Pteroptochina?, Formicariina?, Dendrocolaptinfe, and 

 bynallaxma? all agree in common with the smaller Cotinc^idfe 

 while the Philepittida? markedly differ therefrom. * ' 



Now among the Cotingid^e this palato-pterygoid articulation 

 appears under three forms. In what is doubtless the most 

 primitive the shaft of the pterygoid is continued forwards 

 precisely as in the Philepittida? (p. 142) ; and this is well seen in 

 Uumnorhynchus for example, and, in a slightly more specialised 

 form, m Calyptomena among the Euryla?mida?. In Cotingids, such 

 as Aulm or Lathria, we have apparently the intermediate stage 

 between that seen in FMUpiUa and Chasmorhynchits on the one 

 hand and that of the smaller Cotingids, &nch. s,^ Hadrostomus, and 

 the Formicariinfe— and the types associated therewith in this 

 connection— on the other. In this intermediate stage the ptery- 

 goid impinges against the parasphenoidal rostrum, and is then 

 continued forward in the form of a pedate plate, articulating with 

 what IS evidently a large hemipterygoid fused with the palatine 

 by means of a smuous joint. In the smaller Cotingids, and in 

 types such as Tkamii ophihts a.nd Pteroptochus, this joint has become 

 obliterated by anchylosis. ' 



_ I cannot recall a similar fusion between pterygoid and palatine 

 m any of the higher Passerines, but it occurs with some frequency 

 among the Coraciiform birds, as, for example, in the Capitonida; 

 and ±>ucconid8e. 



The palatine has a scroll-shaped body turned with its concavity 

 msvards, and, fusing with the hemipterygoid, forms an articular 

 surface whereby it is enabled to glide backwards and forwards 

 along the parasphenoidal rostrum. The ventral free edge of the 

 scroll forms, with that of the opposite palatine, a deep channel 

 ^long the roof of the palate immediately behind the vomer 

 From the outer convex surface of this scroll there is given off 

 near its anterior border, a narrow horizontal lamina, which sends 

 a short spur backwards to form the transpalatine process (W K 

 Parker) and a long, slender rod forwards to fuse with the palatine 

 process of the premaxilla. Except in the Pittida?, the maxillo- 

 palatme processes lie so far back that their free ends touch or 

 almost touch, the antero- inferior angle of this palatine scroll • but 

 in the group in question these processes have shifted forwards so 

 that their free ends are far removed from any relation with this 

 portion of the palatine. The transpalatine spur is especially lono- 

 m Xtphorhynchus (text-fig. 50,/, p. 140), and this is apparently 

 correlated with the remarkable form of the beak. 



The Quadrate.— As in the Eurylajmida?, though' not in so marked 



