430 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, 



Rhynchcea, Limosa, Tringa, Machetes, Phalaropus, Strepsilas, To- 

 tanus, Himantopus. 



The Cranes almost always lack basipterygoid processes and the 

 corresponding facets upon the pterygoids, the only exception I have 

 met with being Grus antigone. The Rails are always devoid of 

 basipterygoid processes. In other points the palates of these birds, 

 of Eurypyga, of the Kagu, of Psophia, and of Otis are similar to 

 that of the Plover. The angle of the mandible, however, is obliquely 

 truncated, and not produced into an upwardly curved process. 



In the Gulls, the Divers, the Grebes, the Auks, and the Penguins, 

 the bones which form the roof of the mouth have the same general 

 arrangement and form as in the Plovers. But they are devoid of 

 basipterygoid processes ; and iu the Penguins the pterygoids be- 

 come much flattened from above downwards. 



Fiff. 10. 



Fie:. 11. 



Alca forda. 



Larus rissa. 



Views of the inferior aspect of the skull in Alca torda (fig. 10) and Lams rissa 

 (fig. 11), of the size of nature. The letters have the same signification as in 

 the figure.s of Charadrius, a comparison with which will bring out the fun- 

 damental resemblance of the three skulls better than a description can do. 



But the ProcellariidcB differ from the families which have just 

 been enumerated in the great expansion of the maxillo-palatines, 



