/ 



16 Mr. W. P. Py craft on the 



the lachrymal, of which no trace remains (PI II. fig. 9, 

 a.p.). In a much-damaged skull of Granclala coelicolor I 

 find the lachrymal represented by a minute scale. 



The palato-pterygoid articulation is formed, as in the typical 

 Passeres, by the extension of the distal end of the pterygoid 

 into a slipper-shaped plate embracing the parasphenoidal 

 rostrum. The anterior edge of the plate is opposed to one 

 side of the triangular plate of bone which rises up from 

 the dorsal surface of the palatine so as to be closely applied 

 to the rostrum (PI. II. fig. 9, It.pt.). This triangular plate, 

 though now forming part of the palatine, is evidently the 

 remnant of the liemipterygoid. Sialia, Grandala,&ndEritkacus 

 resemble Ze/cdonia in the presence of this triangular vestige 

 of the hemipterygoid, but in the genera Turdus and Merula, for 

 example, no such vestige remains, and the pterygoid articu- 

 lates with the palatine by the approximation of two oblique 

 and almost linear glenoid surfaces, that afforded by the 

 palatine being developed upon the hinder end of its distal 

 border (PL II. fig. 12). 



The Sternum and Shoulder- girdle (text-fig. 8, p. 17). — 

 The sternum of Zeledonia affords indubitable evidence 

 that this bird possesses but limited powers of flight, inas- 

 much as the keel, relatively to the size of the corpus sterni, 

 is extremely small. Compared with the keel of Sialia, 

 Erithacus, Pratincola, Phylloscopus, for example, the extent 

 of the reduction which has taken place is very striking. 

 While in Zeledonia its free edge is slightly concave, in the 

 several forms just referred to it is markedly convex. Again, 

 in Zeledonia the keel decreases in depth rapidly from before 

 backwards, so that for about one-third of its length it is 

 little more than a median ridge of bone. In any of the 

 forms compared above it will be noticed that the keel is 

 continued backwards to the extreme end of the sternal plate, 

 there to fan out into a V-shaped plate. 



The peculiar shape of the wing further strongly supports 

 the view that this bird has gone far on the road to Sight- 

 lessness. In this connexion it is interesting to note that 

 the reduction of the wing-area correlated with this lack 



