428 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 1 I, 



Fig. 8. 



Under view of part of a skull oi' Charadrlns phtvialis, partiall_y dissected and 

 enlarged. The letters as before, except /?, the basisphenoidal rostrum. The 

 left palatine bone is removed, so as to expose the whole under face of the 

 niaxillo-palatine and prefrontal processes, and the left half of the hinder 

 split moiety of the vomers. 



extremity of this process coalesces with the maxillary and premax- 

 illary bones of its own side. The vomer is deeply cleft behind, and 

 embraces the sphenoidal rostrum by its two slender forks (fig. 8). 

 In front it becomes flattened and slightly decurved (fig. 7), ending 

 in a point opposite the level of the union of the palatines with the 

 maxillaries and premaxillaries. Immediately behind the place at 

 which the maxilla {Mx) gives off its ascending process to join the 

 external descending process of the nasal {No), it sends a slender 

 stem of bone inwards ; and this almost immediately expands into the 

 oval, scroll-like, maxillo-palatine plate (Map'), the convex face of 

 which looks upwards and inwards, while its concave face looks down- 

 wards and outwards. The maxillo-palatine has an abruptly truncated 

 posterior free edge, while in front it tapers ofl^ and becomes united 

 with the upper surface of the maxillary process of the -palatine 

 (fig. 8). In the middle line, its rolled edge, which lies on the inner 

 side of the maxillary process, comes very near that of its fellow ; but 



