OSTEOLOGY 147 



where the articulation with the basipterygoid facets occurs ; 

 it is usually towards the middle of the bone ; but in the emu, 

 in the Anseres and Galli it is quite at the end of the bone, 

 the end nearest to the palatines. The palatines differ greatly 

 in shape and in breadth. Among the Anseres and Galli the 

 internal lamina which meet in the middle line above the 

 basisphenoids are practically absent, being only represented 

 by a more or less faintly marked ridge. In other, birds these 

 regions of the palatines are well marked, and may meet for 

 a considerable space in the middle line, and, as in Steatornis, 

 an anterior portion of each bone may come into contact in 

 the middle line further forward, thus giving rise to what has 

 been termed double desmognathism, the maxillo-palatines of 

 course forming the other junction in the middle line in front 

 of them again. In most birds perhaps the palatines are 

 gradually rounded off behind, but in the Ardeidae and in 

 Bhinochetus, &c., they are as it were sharply cut across 

 behind this edge, being at right angles to the long axis of the 

 bone. In many Passeres and in some other birds there is a. 

 well-developed postero-lateral process of the bone, which has- 

 been termed transpalatine ; this, if it came into contact with 

 the jugal arch, as it nearly does in some Passeres, would bear 

 the strongest likeness to thje transverse bone of reptiles .. 

 The palatines are occasionally, but rarely, fenestrate, e.g.. 

 Anous, Eurypyga. 



The vomer varies from complete absence (Colius) to very 

 striking presence. When present there is every grade be- 

 tween a thin splint and a broad flat bone, which in the latter 

 case is often obviously formed of two lateral halves. These,, 

 however, do not appear to remain completely separate except 

 among the Pici (q.v.), where they are smallish splints. But 

 not only among the ostrich tribe, but in Hesperornis and 

 passerines the vomers are double in the young. A series of 

 small bones lying between the palatines, and called interpa- 

 latines and septo-maxillaries by Paekbr, may be regarded 

 as belonging to the vomerine series. They are unpaired 

 ossicles which continue, though with a hiatus, the vomer 

 backwards. 



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