302 Annals of the Carnegie Museum. 



As compared with the other elements of the skull, Pluvnicoptenis has 

 a big quadrate. Its orbital process is broad, thin and quadrilateral in 

 outline, with the internal free extremity abruptly pointed ; its mastoidal 

 portion is compressed in the oblique antero-posterior direction, and 

 distinctly exhibits the double head for articulation with the skull. At 

 its mandibular base the arrangement of the facets, as well as their 

 forms, differ very materially from what we find in either the anserine 

 birds or among any of the ordinary Ibises, though they agree better 

 with the latter than they do with the former. This is somewhat re- 

 markable from the fact that the orbital process of the quadrate in our 

 Flamingo is more like that part of the bone as seen among Swans, 

 Geese, and Ducks than in such an Ibis as P/egadis. Both the (juadrates 

 and the pterygoids of ^yV/A? {Plafalea) are manifestly different in their 

 important characters when compared with those bones in either the A/i- 

 sercs ov the Ibises, or even the Flamingo. For their posterior moieties, 

 in the middle line, the palatines are pressed together with the greatest 

 intimacy, and we find here, coossified with them, the vomer which will 

 be described further along. Viewing these bones from beneath we ob- 

 serve that the meeting between them is for the entire length of the 

 "ascending process" of each, to include posteriorly the pterygoidal 

 processes. Their "bodies" are flat, lie in the horizontal plane, are 

 each rather broader in front than behind, and are likewise nearly 

 parallel to each other. A very considerable median interval, or open 

 space, separates the body of one palatine bone from that of the other, 

 while anteriorly they pass beneath the maxillaries to become completely 

 fused with the premaxillaries and maxillo-palatines. The "postero- 

 external angle " of either palatine is rounded off", and both the internal 

 and external laminre are but feebly developed. 



This by no means applies to the ascending process upon the superior 

 aspect of the bone, for this is a most elegant scroll-like affair, that 

 springs from almost the entire outer margin of the supero-external 

 border of the body of the bone, to sweep upwards and inwards, to 

 meet and fuse with the postero -superior edge of the vomer. The an- 

 terior border of this ascending process of either palatine, is seen to be 

 a deep, loop-like curve, with its concavity directed to the rear. The 

 inner line of the curve is continuous with the superior border of the 

 vomer, while the outer sweep of the curve passes across the body of 

 the palatine to finally become continuous with the mesial edge of the 

 same. 



