SHUFELDT : OSTEOLOGY OF THE STEGANOPODES 1-^5 



Regarding this skull from a superior view, we see in it a foramen in the superior 

 mandible, near the site of the narial opening of the majority of other birds. From 

 this aspect we also have a good view of the wonderfully perfect cranio-facial hinge 

 of this bird. 



Posterior to this is a broad, smooth area, very slightly convex, and showing in 

 some species numerous venations like those on the bill of S. cyanosis. This surface 

 extends from the cranio-facial hinge to the anterior border of the crotaphyte fossa?, 

 while laterally it is bounded by the margins of the orbits. 



This view also shows the extent and form of these crotaphyte fossae, and how 

 they are separated from each other in the median line, simply by an extension 

 backward of a very narrow strip of the general surface that lies beyond them. They 

 merge with each other in some specimens of S. piscator. They are bounded behind 

 by conspicuous and sharpened crests that curl slightly forward, and are best marked 

 laterally, becoming very low as they near the upper part of the supra-occipital 

 prominence. 



The under view of the skull reveals a number of interesting points. We find 

 that the anterior portions of the palatines are parallel to each other, separated by a 

 median cleft of a width equal to either one of them, and which becomes pointed 

 behind. 



Their anterior ends do not merge into the premaxillary beyond until they are 

 well past the points where the maxillaries are inserted. These anterior portions are 

 thin, horizontal plates, being directly continuous with the horizontal and fused 

 palatine bodies behind. This latter portion shows a small median carination just 

 in front of the united heads, and the postero-external angles are rather sharp, being 

 pointed directly backward. 



Anteriorly, the pterygoidal heads meet each other and the fused palatines, the 

 three forming a groove on their upper sides for the rostrum. At their outer ends 

 each pterygoid offers a shallow cup to form the usual articulation with the quadrate 

 of the corresponding side. 



Professor Parker found that " in Sida alba the basitemporals are as little devel- 

 oped as in the Dromseidw, less than in any other carinate bird. Behind each moiety 

 there is a large oval opening, not far in front of the occipital condyle; this exposes 

 the loose diplose within. The small Eustachian tubes open at a little distance from 

 each other, in a wide, shallow fossa, on the part where the three elements of the 

 parasphenoid meet." The description of these details agrees with the skull of the 

 specimen before me. Professor Parker, however, was fortunate in having the skele- 

 ton of the ear-parts in his specimen, and, of them, he says that "in Sula alba, the 



