1867.] PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. 429 



it remains perfectly distinct from the other maxillo-palatine and 

 from the vomer. The plate is perforated by four holes, between 

 which a sort of St. Andrew's cross of bone is left (fig. 8). 



It follows from this description that, in the dry skull of the Plover, 

 the blade of a thin knife can be passed, without meeting with any 

 bony obstacle, from the posterior nares alongside the vomer to the 

 end of the beak. 



On each side of its commencement the basisphenoidal rostrum 

 presents a small elevation, terminated by a flat oval facet (fig. 6, x), 

 which represents the basipterygoid process of the Ratitse. A cor- 

 responding facet on the inner edge of the pterygoid bone, nearer its 

 anterior than its posterior end, articulates with this (fig. 6). 



The angle of the mandible is elongated into a slender process, 

 which bends abruptly upwards, and is frequently broken off (fig. 6). 



The Pluvialine form and arrangement of the maxillary, palatine, 

 and pterygoid bones just described are substantially repeated in the 

 following Pressirostres and Longirostres of Cuvier : — Charadrius, 

 Q^dicuemus, Va7iellus, Hcematojms, Cursorius, Scolojiax, Numenius, 



Fig. 9. 



Under view of the skull of Grus pavonia. From a specimen in the Museum 

 of the Royal College of Sm'geons. 



The letters as before. 



