338 



STRUCTURE AND CLASSIFICATION OF BIRDS 



I'mx. 



at the beginning of the neck ; on the breast each half gives off 

 a strong lateral branch. 



All the Charadriidse, and indeed all the Limicolae, 1 are schi- 

 zognathous ; but many of them have not the typical condition 

 of the vomer which accompanies as a rule the schizognathous 

 skull. In the woodcut (fig. 169) a few exceptions to this are 



given, which range from the typical 

 condition observable in Sterna to an 

 excavated extremity, such as charac- 

 terises Recurvirostra. In Chionis the 

 vomer ends in the typical manner, i.e. 

 in a point ; but it is exceedingly broad 

 before its termination, and therefore 

 quite unusual. 



In TJiiuocoms and Attagis the 

 vomer is short and broad, and almost 

 passerine in form. 



The maxillo-palatines are, as a 

 rule, thin and scroll-like plates, which 

 are bent downwards and often defi- 

 cient in ossification, leaving holes here 

 and there. The palatines have a 

 spout-like process, extending upwards 

 towards the base of the skull, which 

 is especially well marked in CEdic/n - 

 m-us. The Limicolse are nearly all of 

 them schizorhinal, the delicate bar of 

 i- the premaxilla being inserted at a 

 different plane from the attachment 



Nip 



FIG. 168. UNDEB VIEW OF 



alis (AFTER HUXLEY). 



Pm.r. premaxilla; V<>. vomer ; MX, 

 maxilla: I'l, palatine; R. ros- of the nasals to the fl'Olltals. Ill the 

 triiiu ; Xa, nasal ; M.rp, ruaxillo- 



, eetetimioia. Characlriidse proper there are a pair of 



largish occipital vacuities, one on either side of the foramen 

 magnum. These same birds have basi-occipital processes, 



1 SHUFELDT (' Contributions to the Comparative Osteology of Arctic and 

 Subarctic Water Birds,' J. Anat. Phys. 1889 and 1890) figures a few skulls of 

 Limicolffi. See also the same, ' On Apliriza virgata,' Joiirn. J/or/i/;. ii. p. 311. 

 See also 'Osteology of Niunenius,' &c., Journ. Anat. I'Jn/s. 1885, p. 51; 

 ' Observations on the Osteology of Podasocys mmtan/is,' ibid. 1884, p. 86. 



