322 PEOF. W. K. PAEKEE ON .^GITHOGNATHOUS BIEDS. 



Moreover it is evident that in these songless passerines we have not travelled far 

 from the level of the great j)luviaHne 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 (tr). Let this state of things be compared with what 

 the reader will see in Ocydromus australis, Gavia ridibunda, Uria troile, and Alca 

 torda, and he will see at a glance how near this elegant little Southern passerine comes 

 to the more specialized pluviaUne " 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, s.mx). 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 

 a rounded 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 laminae. 

 This type is spgithognathous 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 {t.pa) ; 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 prsepalatine 

 (pr.pa). This is a most slender bar, which, from a compressed, becomes a depressed 

 band, ankylosed in front to the prsemaxiliary. 



The external bones, prsemaxillary, maxillary, and jugals, are all ankylosed together. 

 The maxillo-palatine process (nnv.p) is delicate and falcate ; it is subpedunculated ; the 

 body of the bone, where it arises, is pneumatic. The palatine processes of the prac- 

 maxillary {p-px) are very well marked and extremely slender. 



The lateral ethmoid (fig. ^,p-p) has a concave outer edge — an uncinate " lower angle " 

 (o. u), a large common foramen above, and is not flanked by any apparent lacrymal. 



On comparing this type with the large Bendrocolaptes, it is easy to see that most of 

 the difl'erence 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 is a creature of the " Notogsea," 

 and belongs to a lower level. 



