SKULL OF THE ZGITHOGNATHOUS BIRDS. 259 
maxillary is very variable if the whole Class be considered; but in by far the majority of 
the Coracomorphe the palatine runs on the inner side of that process. In this species 
and in the next, both of them belonging to the Meliphagide, the palatine runs on the 
outer side (Plate XLVII. figs. 1-4, p, pa, pr.pa): these are the only instances found 
by me at present amongst the Passerines. This exceptional character in the Melipha- 
gide is not so striking as the uniformity of the rest of the group as to a modification 
so slight; but altogether their close kinship is evident in all their structure, and their 
variations, from family to family, gentle in the extreme. 
The following Table will show how mobile is the articulation of the splintery ele- 
ments of the fore palate :— 
1. Apex of prxpalatine some distance behind palatine plate of premaxillary. 
Examples. Struthio camelus (adult), Rhea americana, Dromeus ater, Casuarius Bennettii. 
2. Apices of prepalatine bar and palatal process of premaxillary united by suture. 
Examples. Struthio camelus (one third of incubatory period), Gallus domesticus (at time of 
hatching), 
3. Prepalatine bar passing over the palatal process of premaxillary, as well as to the inside. 
Examples. Falco tinnunculus (fledgeling), Ardea cinerea (fledgeling). 
4. Prepalatine bar let into the wnder surface of the large palatal process of the preemaxillary. 
Example. Platalea leucorodia. 
5. Prepalatine bar passing outside the palatal process of preemaxillary. 
Examples. Tinamus variegatus, Gallus domesticus (adult), Picide and Yungide, Meliphagide. 
6. Prepalatine bar passing inside the palatal process of preemaxillary. 
Examples. Dicholophus cristatus and the Aétomorphe generally, the Coracomorphee (with the above 
exception), Cuculus canorus, Oorythaix buffoni, Megalema asiatica, Caprimulgus europceus, 
Trochilus (Patagona) gigas, Colymbus septentrionalis. 
As in those low types, the Rhea and the Tinamou (‘Ostrich’s Skull,’ pls. iv., xv.), 
the palatine process of the premaxillary (Plate XLVII. figs. 1 & 2, p.px) is very large, 
long, and lathy. Between the two, at their root, there is a short median process, 
which hides the recurrent horns of the trabecule, and ends the groove in which the 
prenasal cartilages lay. All the fore part of the long decurved rostrum is narrow, the 
dentary edge (d.px) sharp; the median line deeply scooped. The frail maxillary (ma) 
is entirely confluent with the rostrum in front and the jugal (j) behind ; at its middle 
it is bowed somewhat outwards, and expanded inwards: this wide part has a large 
fenestra, and a long maxillo-palatine bar (ma.p); and nearly half the length of this is 
taken up by the filiform pedicle; the greater half is a free lanceolate leaf of bone. 
This process here is more retrally developed than usual; it is peculiarly ornithic. At 
VOL. X.—PaRT vI. No. 2.—June 1st, 1878. 20 
