296 PROF. W. K. PARKER ON 4&GITHOGNATHOUS BIRDS. 
and the styliform crura long and delicate; the fore margin is clearly notched; it then 
suddenly widens, and on each shoulder there is a triangular snag with its projecting 
base looking outward and fixed and grafted upon a sigmoid spatula of cartilage (v. ¢). 
This compound lyre-shaped vomer is strongly attached to the nasal floor (al. n) by a 
broad and short ligament composed of connective fibres. In the adult (fig. 9, v) the 
angular snags have been segmented off as small “ septo-maxillaries”’ (s.ma), the body 
of the bone has become very thick, and the crura stronger. The inferior surface is 
subcarinate, the superior scooped. Here the main difference between this vomerine 
arrangement and that of the Passerines is, that the bony substance has affected the 
cartilaginous segment, but not the nasal labyrinth. Yet the amount of metamorphosis 
seen in these birds is greatly in advance of the pupal simplicity of the Rhea; even where 
the vomerine cartilage occurs in a high type, as in the Celebesian Woodpecker (Hemi- 
lophus fulvus), there is no morphological union with the vomerine bones. 
The pterygo-palatine arch is very strong in its posterior half, and of extreme tenuity 
in front. The suspensorial segment, “ pterygoid” (figs. 1 & 9, pq), is not tip-tilted 
as in most of the Coracomorphe, but agrees in this respect with the forms that lie 
in its own lower stratum, the apex being compressed and bilobate, so as to abut against 
the quadrate up to its orbital process. For the rest, its form is exactly that of a 
Pigeon or Plover; but it appears to be gallinaceous in one important aspect—namely, 
that the mesopterygoid spur is fore-shortened, and is here formed into a crest, convex 
without and concave within, where it forms a gliding joint on the swollen basifacial 
beam (fig. 11, pg, pa.s). But in the young Hemipodius varius it is a long separate bone 
(fig. 13, ms.pq); and what is unusual is its coalescence with the pterygoid again, and not 
with the palatine. This being the case, the narrow outturned postpalatine bar fits but 
loosely to that beam, but converges to meet its fellow below it, to form a fibrous com- 
missure, symmorphic of a very early condition of the lyriform trabecular arch. The 
small “interpalatines,” which are inbent snags, are of less extent than the overlying 
ethmopalatine lamin, which articulate with the feet of the vomer (figs. 1 & 9, i.pa, 
e.pa,v). Opposite these the palatines bend gracefully round to pass forward as the long 
prepalatine styles (pr.pa); there is therefore no rudiment of the “ transpalatine angle ;” 
yet the groove between the outer and inner edge on the lower face of the bone is rather 
deep. In front these bones reach to the solid part of the praemaxillaries, and stretch 
themselves in front of their chief splints, the maxillaries (figs. 1 & 9, pr.pa, ma). ‘These 
latter bones are simple models, out of which, by further extension of bony matter, the 
maxillaries of any kind of “ Carinate” bird might be evolved. Each frail bony bar has 
the usual processes and parts, namely :—the main or dentary portion, fish-like in lying 
within the preemaxillary; the ascending facial process, which articulates with the 
descending crus of the nasal (fig. 11, x.ma:); the conjugational “ maxillo-palatine ” hook 
(ma.p); and the retral jugal style (7. ma), or zygomatic process. 
In the young Turnia (fig. 1, ma.p) the former are very slender styles, blunt-pointed 
