14 SHUFELDT — OSTEOLOGY OF THE CUCKOOS. [Jan. 4, 



that separates the anterior terminations of the maxillo-palatines. 

 This aperture has irregular, jagged edges, and through it we may- 

 see some of the open, spongy bone tissue that partially fills the 

 hinder portion of the core of the superior mandible. At the sides, 

 the posterior processes of the dentary parts of the premaxillary 

 overlap the maxillaries. They are long and triangular, with their 

 apices to the rear. 



Returning to the maxillo-palatines, we find them to be, upon this 

 aspect of the skull, two very sizable, elongated, subcylindrical 

 masses, composed of an internal spongy tissue, but encased in an 

 outer covering of an extremely thin layer of compact tissue. 

 They lie parallel to each other and to the median plane, nearly 

 filling the interpalatine space. Anteriorly, they are separated by 

 the vacuity already described, while behind, their free and rounded 

 extremities slightly diverge from each other, they being in contact 

 in the median line for the middle thirds of their lengths (PI. I, Fig. 

 2). From their upper sides is developed a mass of open spongy 

 tissue; this is continuous with a similar structure that is found 

 within the superior mandible ; it reaches out, on either side, to 

 abut against the inner surfaces of the nasals ; it joins the horizontal 

 plates of the maxillaries, and finally supports a median vertical 

 plate of bone that stands just beyond the rhinal chamber proper, 

 this latter space being free from its encroachment, as it is from any 

 development of the ethmoid behind, beyond its lateral wings. 



The anterior half of either palatine is quite a broad, flat, hori- 

 zontal plate, the distal end of which indistinguishably fuses, and is 

 directly continuous with the horizontal portion of the premaxillary. 

 To its inner side also, in this locality, it completely anchyloses 

 with the corresponding maxillo-palatine (PL I, Fig. 2). For the 

 most part, however, its inner and outer edges are free, not coming 

 in contact by the inner one with the maxillo-palatine, though it is 

 parallel to it and separated by an extremely narrow interval, while 

 its outer one neither touches the lacrymal nor the maxillary, but 

 occupies a plane inferior to both. 



The posterior half of a palatine also lies mainly in the horizontal 

 plane, but its under surface is a concave one, and its upper corre- 

 spondingly convex. Its outer free edge, directly continuous with 

 the outer edge of the anterior half of the bone, sweeps by a gentle 

 curve round the " postero-external angle" of the palatine to its 

 head. Huxley was in error when he stated (P. Z. S., 1867, p. 



