PROF. W. K. PARKER ON GITHOGNATHOUS BIRDS. 320 
goids (fig. 1) are elegantly hooked behind, and terminate in front by ankylosis; this ele- 
ment and the rest fall back into the original simplicity of this bar. The mesopalatine 
region (fig. 1, pa) is large, both fore and aft and transversely ; the postpalatine ridges 
are moderately developed ; and the transpalatine processes are strong, retral, somewhat 
out-turned spines; they are continued as an outer ridge to the broad part, and then 
the bone is passed forwards as a stiff bar, gently converging to its fellow: thus there is 
but a slight sinuosity from the terminal point of the bar and that of the retral process. 
The space between the outer ridge and the interpalatine ridge is well scooped ; the spurs 
are short. ‘The arched ethmo-palatine is notched in front. The investing facial bones 
are strongly ankylosed together; the maxillo-palatine processes (ma.p), like those of 
Muscisavicola, are flat, gently curved, and knife-like; they do not form a strong con- 
nexion with the shoulders of the vomer. : 
Thus, with its own peculiarities and an evident tendency towards the Southern-Crow 
type, this bird is related very intimately, right and left, to the other members of the 
family ‘‘ Dendrocolaptide.” 
The lacrymal (fig. 4, 7) is very small in Homorus, as in many Coracomorphe. 
Example 15. Gymnorhina tibicen. 
Habitat. Australia. Group ‘ Oscines,” Miiller; family ‘“‘ Gymnorhinide.” 
Here is another eastern type, which is merely a more highly specialized, a more com- 
pletely metamorphosed dendrocalaptine bird. Suggesting to the observer its own name 
(Crow) with the modifying epithet “ Piping,” this is yet a bird which is the culmina- 
tion of a very different branch of the Agithognathe from that of the true Crows of the 
Old World (‘“‘ Arctogza”). There are not many internodes between this upper type and 
the Chilian and Brazilian birds that grow out below it. Two of the further speciali- 
zations that characterize it from these are a greater intensity of ossification, and the 
metamorphosis of the contractor trachew muscle into the motors of the “ syrinx.” 
Comparing the skull of this bird with that of Homorus, in a general way, as to form 
and strength, the difference is very similar to that between those of Gecinus viridis and 
Picus major; yet there is, altogether, in Gymnorhina a rise, both zoological and mor- 
phological. 
The basitemporal and parasphenoidal regions (4.¢, pa.s) in these birds would, to a 
hasty observer, seem to differ only in size; so much is onea repetition of the other. Yet 
a second look shows that in Gymnorhina the basipterygoid processes (Pl. LX. fig. 5, b.pq) 
have found their proper ornithic position, namely on the parasphenoid (pa.s). This bar 
itself is also more elegantly narrow than in Homorus (fig. 1). Yet the presence of these 
basipterygoids, even as prickly rudiments, is a rare thing amongst the Coracomorphe, 
and bespeaks a nearer relationship to the plebeian types below than obtains in the true 
Crows of the Old World. P 
In the absence of the young of this bird no other type could have been found more apt 
