OCR Text |
Show 428 PROF. H U X L E Y O N T H E CLASSIFICATION O F BIRDS. [Apr. 1 1, Under view of part of a skull of Charadrius pluvialis, partially dissected and enlarged. The letters as before, except B, tbe basisphenoidal rostrum. The left palatine bone is removed, so as to expose tbe whole under face of the maxillo-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 premaxillary 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 (Na), it sends a slender stem of bone inwards ; and this almost immediately expands into the oval, scroll-like, maxillo-palatine plate (Mxp), the convex face of which looks upwards and inwards, while its concave face looks downwards and outwards. The maxillo-palatine has an abruptly truncated posterior free edge, while in front it tapers off 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 |