SKULL OF THE ^GITHOGNATHOUS BIEDS. 261 



is elegantly undulating in form. The large postpalatiae keels terminate below, in front, 

 in a blunt interpalatine process Qj^.j^fc, i.pa) ; a strong ligament binds the retral maxillo- 

 palatine (mw.j}) to this spur. The ethmo-palatine, ankylosed to the vomer, does not 

 reach further forward than the isthmus and interpalatine, and is out of view below. 

 The parasphenoid (pa.s) is uncovered from the solid part of the vomer to near the end 

 of the palatines ; but these close in where they meet the pterygoids. The widest part of 

 the maxiUary is fenestrate, as in the last instance ; but the maxillo-palatines have not 

 so long a pedicle, have no spur where they underbind the vomer, and are thick enough 

 to contain air-cells (figs. 3 & 4, «, mx.p) ; their whole form is strongly arched, the 

 roundest part of the bow being at their root. As in the last, the vomer is but little 

 emarginate, a strong contrast to that of the Nectariniidee (Plate LIII.) ; and I 

 strongly suspect that it was ossified from four centres, the two outer being the septo- 

 maxiUaries. The whole bone is oblong, smooth, and, in front, slightly carinate ; its 

 shoulders are grafted upon the inturned lamina of the nasal wall {n. iv). The out- 

 bowing of the bony bars exposes more of the nasal labyrinth below (n. w, a.tb) than in 

 the last instance ; it is entirely unossified. The septum (s. n) is long, deep, and non- 

 alate ; and the recurrent lamina is hidden by the median part of the prsemaxillary mass. 



This skull, generally, is like the last, but has less resemblance to that of the Trochi- 

 lidae; its ethmoidal masses {e.eth,])-^) are, like those oi Acantlwrhynchus, very large and 

 spongy, showing no os uncinatum or lacrymal ; and over the pars plana the olfactory 

 and orbito-nasal nerves pass through one common large space. 



I found the syrinx very perfect in this bird. 



Example 36. Skull of Sericomis humilis (?). Family Sylviidse. Section Oscines ^ 



Habitat. Australia. 



This bird and the next are Australian; then I have to describe several from 

 Panama and the Central- American district. All these, with two species of the Austra- 

 lian genus Petroica, described in the first Part (plate Ix. figs. 9 & 10), come, as to their 

 skull, under one category, however the zoologist may find it necessary to put them into 

 various families. 



Some of them have a " syrinx ;" and in others it is not developed ; but as to their 

 skull, they have much in common, and they are evidently intermediate between the 

 soft-billed Passerines with which we are familiar here, such as Sylvia, Muscicajoa, Mota- 

 cilia, Anthus, and those of South America, such as Muscisaxicola, Synallaxis, Anwretes 

 (Part I. plate lix.), and also the Australian " Meliphagidae," just described ^. 



' This bird has, I find, a perfect syrinx. 



' I must confess that the latter are much nearer to the Sylviines than the South-American TjTannidae and 

 Dendrocolaptidae ; the most archaic Australian type is Menura (Part I. plate Ivi.). The ^yhmcha-t {Pratincola 

 Tuhetra) corresponds very closely with the Central- American types (see Plate XLVUI.). 



2o2 



