l6o SHUFELDT. [Vol. XVII. 



meets the jaw, as well as the os quadratmn and the os jugale, 

 at their point of articulation. It is in this way that the cra- 

 nium itself comes in contact with the lower jaw, a phenomenon 

 which is certainly without parallel in the class Aves, outside of 

 this genus. Owing to the unusual development of this osseous 

 crest, the fossa, in which the aural entrance is found, is of con- 

 siderable width, particularly upon the right side. On the other 

 hand, the entrance to the ear itself is normal upon both sides, 

 and quite symmetrical ; and, as the asymmetry is thus mainly 

 confined to the external osseous crest and its neighboring struc- 

 tures, while the os sqiianiosiim, internally, is normally devel- 

 oped, upon either side, it follows as a result that the inner 

 walls of the brain casket are symmetrical, and the brain itself 

 does not appear to offer anything anomalous in so far as its 

 superficies are concerned. 



The parietal bone upon the left side, on account of the lowly 

 situated osseous crest of the os squam.ostim, is quite pointedly 

 produced anteriorly, though it extends forwards quite to the 

 hinder margin of the orbit ; on the right side, where the osse- 

 ous crest is situated higher up and at the same time placed 

 farther backwards, it is less pointed, though crowded farther 

 to the rear, and as a consequence does not reach to the poste- 

 rior border of the orbit. The alispJienoid is, upon the right side, 

 larger and posteriorly broader than it is upon the left side ; in 

 other respects the orbital crest does not present any asymmetry, 

 that is, beyond the fact that its superior border is extended a 

 little higher up on the right side than it is upon the left. 



The interorbital septum is, anteriorly, quite thin and trans- 

 lucent ; the OS ethmoides has a comparatively thick wall. 



The siipraoccipital {squama occipitis) is pierced by a small 

 supraoccipital foramen (diameter |4 mm.). 



The pterygoid bones are slender, being somewhat compressed 

 from above downwards, thus causing their cultrate edges to 

 turn obliquely outwards and downwards. 



T\iQ palatine bones are very broad; t\\Q pars planes upon the 

 mesethmoid are quite short, and do not extend beyond the ex- 

 ternal palatine borders, when the cranium is viewed upon its 

 basal aspect. 



