338 PROF. W. K. PARKER ON “GITHOGNATHOUS BIRDS. 
Australian passerines, and that whether their song-muscles are developed or not. In 
this first paper I have only space for one more of these, namely Pachycephala; but 
afterwards Sittella and Sericornis will come under notice, besides those very unique types 
Prtilotis and Acanthorhynchus. 
Example 25. Pachycephala fusca (2). 
Habitat. Australia. Group “ Oscines,” Miiller; family ‘“ Laniide.” 
Notwithstanding the superiority of this type over Petroica in the separation of the 
tracheal muscles for song, it is yet, I am satisfied, on the whole, only a slightly modified 
Petroica. Its large skull, shortish beak, and most remarkable vomer are the proofs of 
this. In some respects, Pachycephala is less specialized than Petroica—that is, in its 
palatine arch, both the primary and investing parts. 
On each side of the basitemporal there is the tubular “tympanic” on the “ sipho- 
nium,” with one or two additional ossicles. The basitemporal (Pl. LXI. fig. 7, 6.) 
itself is bat-shaped, as in the “‘ Cotingide” and “ Formicariide ;’ and there are no basi- 
pterygoids on the rounded parasphenoidal beam. The hinge is almost perfect. The 
septum nasi (s. 2) is alate in front ; and the trabecular bone (¢) has appeared in this part 
behind the ale. The recurrent alinasal fold (rc. c) is well marked, and the inturned 
alinasal fold (7. a. /) is narrow; mesiad of this we see the huge alinasal turbinal (a. #) 
with two bony patches. The alinasal scale (Plate LXI. fig. 8, a/.n) externally is unos- 
sified, but of large extent. The inferior turbinals are narrow and very long (7. #4): they 
are mostly soft; but there is a bony patch postero-superiorly. 
A hasty observation might lead to the opinion that the peculiar form of the vomer 
(like baggy Turkish trowsers) was a mere freak of Nature; but its meaning lies deeper 
than this. In Petroica monticola (Pl. LX. fig. 9, v, sma), we have the same form, 
coupled with an alinasal turbinal ossicle close to the angle of the vomer. This curious 
outgrown form depends upon the very large size of the supero-lateral elements, the 
septo-maxillaries (s.ma), which here rival those of Lizards and Snakes. The vomer is 
subcarinate in front, but does not project at the mid line; the bone, especially at its 
edges, is thick and spongy; its upper lobes are scarcely developed: altogether it is a 
slightly masked reptilian structure. 
The pterygoids (Pl. LXI. fig. 7) are like those of Petroica, but shorter; they have, 
like the palatine arch, altogether a very cotingine appearance. 
The postpalatine keels are sharp and deep; the mesopterygoid and ethmo-palatine 
lamine are low, the interpalatine spurs abortively developed, as is the transpalatine (¢.pa), 
the bony bridge across of slight extent, and the prepalatine bar a narrowish subsinuous 
bar. The maxillo-palatine processes (map) are broad-based, thick and clumsy, not so well 
developed as in Petroica (Pl. LX. figs. 9 & 10, ma.p), and on a level with those of 
Pachyrhamphus (“ Cotingide”) and Thamnophilus (‘ Formicariide”). The continuously 
bony jugum (/) is feeble and sinuous, and but little inturned behind. The prefrontal, 
