2 PROF. W. K. PARKER ON AGITHOGNATHOUS BIRDS. 
32 
Moreover it is evident that in these songless passerines we have not travelled far 
from the level of the great pluvialine stratum ; for the “ notch” is only marked out by bony 
tracts (fig. 8, p.e, s.n), the fore part of the perpendicular ethmoid being separated by 
synchondrosis, and not by fibrous tissue, from the postero-inferior septal bone—a tra- 
becular tract; and this has in front of it two bones belonging to the common septum of 
the nasal sacs. The foremost of these, as usual, ossifies the recurrent lamina, and the 
alate region of the septum nasi (#7). Let this state of things be compared with what . 
the reader will see in Ocydromus australis, Gavia ridibunda, Uria troile, and Alea 
torda, and he will see at a glance how near this elegant little Southern passerine comes 
to the more specialized pluvialine “Schizognaths.” The lateral parts of the nasal 
vestibule are all soft; the part of the compound vomerine bone joined to the inturned 
alinasal wall is a distinct, transversely placed bone, somewhat reniform—the septo- 
maxillary (fig. 7, sma). The vomerine elements themselves have ossified the fore part 
of the vomerine cartilages; and these serrated blades of bone lie on a higher level than 
the thick part of the vomer, the commissural part of which is squared in front, and has 
arounded notch behind. The shoulders of the bone pass gently into broad crura, which 
stride along the parasphenoid, and are welded to the coiled ethmo-palatine lamine. 
This type is egithognathous in a complete manner; but it belongs to the first variety. 
The pterygo-palatine arch displays the same southern characters as the trabecular. 
The pterygoid has a long, delicate hook, a straight shaft, spreading in front ; its fore edge 
is free ; and the palatines, which, although typical in borrowing a mesopterygoid lamina, 
have long, rod-like transpalatines (¢.pq@) ; these spurs are turned outwards. ‘The broadish 
floor of the nasal passage is twice notched, in a shallow manner, behind, and sends a 
sharp interpalatine spur (i.pa) forwards. ‘The roof of the tube is elegantly arched, 
passing forwards to combine with the vomer; the postpalatine keels are large and 
divaricate (pt.pa). 
The thick edge of the outspread mesopalatine region passes on into the prepalatine 
(pr.pa). This is a most slender bar, which, from a compressed, becomes a depressed 
band, ankylosed in front to the premaxillary. 
The external bones, premaxillary, maxillary, and jugals, are all ankylosed together. 
The maxillo-palatine process (mw.p) is delicate and falcate; it is subpedunculated ; the 
body of the bone, where it arises, is pneumatic. The palatine processes of the pre- 
maxillary (p.pa) are very well marked and extremely slender. 
The lateral ethmoid (fig. 8, p. p) has a concave outer edge—an uncinate “ lower angle” 
(0. #), a large common foramen above, and is not flanked by any apparent lacrymal. 
On comparing this type with the large Dendrocolaptes, it is easy to see that most of 
the difference between the two arises from mere size. All that is independent of that 
cause, however, is of a very instructive nature; and much as this elegant little bird 
resembles our Old-World Chats, Wagtails, Pipits, &c., it isa creature of the “ Notogea,” 
and belongs to a lower level. 
