SKULL OF THE ^GITHOGNATHOUS BIRDS. 253 



separate " palato-maxillary (p.im;)" This is a character to be found in several families 

 of the Coracomorphae, as I shall soon show. Its presence suggests some delicate bond 

 of affinity between the families where it is found ^. 



The maxillary is but a feeble bone, ending in a long, slender jugal style, formed by 

 its own process and by the free jugal {mx,j). The maxillo-palatine processes {mx.j)) 

 are bent both backwards and inwards, in the usual manner, and end in a directly retral 

 club, which is large, pneumatic, and has two inferior air-openings. The large vomer 

 (d) has the ox-face shape, and is grafted on the inturned alinasal lamina {i. al) without 

 showing any distinct septo-maxillary ; its distinctness, however, may be sought for too 

 late, or too early. The recurrent laminae (trabecular horns) could not be seen ; but the 

 fore part of the trabecular bars {tr, s. n) showed a fine foliation in front, making the 

 septum nasi broadly alate. These alse remain soft ; but the septum, which is fenestrate, 

 is ossified. There is no distinct " os uncinatum ;" but clinging to the front of the antor- 

 bital is a thoroughly Corvine lachrymal (fig. 2, p.p, I) ; its head rests against the descend- 

 ing crus of the nasal (n), and its foot upon the jugal process of the maxillary and the 

 jugal apex (_;'). The open (bony) nasal passage (e. n) shows, now that the cartilaginous 

 nasal labyrinth has been removed, an elegantly oval space, as in the Crows. 



Example 29. Skull of Violet Tanager (Euphonia violacea). 



Habitat. Barbadoes. 



This small bird shows, very instructively, the Tanagrme type of skull (Plate XLVI. 

 fig. 3). The flat, strap-shaped prsepalatine bar {pr.pa) narrows greatly backwards, and 

 the processes sent from the main bar to the skull-balk are of small antero-posterior 

 extent; these are the lower or interpalatine keels, and the upper or ethmopalatine 

 shells {i.pa, e.pa) ; the latter are confluent with the vomer {v). 



The interpalatines run into large, steep, almost semicylindrical postpalatine plates 

 {pt.pa), as in so many Southern Passerines ; the transpalatine spur {t.pa) is slenderer, 

 straighter, and longer than in Tanagra cyanoptera. Beneath the root of the clubbed 

 maxillo-palatine (?/a\^) there is a small spicular palato-maxillary {p.mx), partly con- 

 fluent with the outer edge of the palatine bar. The vomerine moieties show a septo- 

 maxillary {v, s.mx, i. al) confluent with the substance of the intumed alinasal lamina, 

 which is soft beyond that bone. These thick wedges of bone are scooped antero-infe- 

 riorly and dovetailed with the diverging vomerine crura. Here the vomer is unusually 

 emarginate and cloven. 



Example 30. Skull of Stephanophorus leucocephalus. 

 Habitat. Brazil. 

 The skull of this Tanager (fig. 4), which is a little smaller than Tanagra cyanoptera 



' In the Woodpeckers and Wrynecks this bene exists, but only on the left side (see Trans. Linn. Soc. 1875, 

 ser. 2, vol. i. pis. 1-5, pp. 1-22. 



2x2 



