274 OSTEOLOGY OF TUBINARES AND STEGANOPODES. 



Profundity of the orbit is much enhanced by the enormous post- 

 frontal wings in this Albatross, and these are formed precisely in the 

 same way as we found them to be in the Puffins, only here the base of 

 the latter half of the nasal pic remains. 



The crotaphyte fossa is nearly entirely lateral. It is broad, though 

 feebly impressed, and separated as usual from the nasal glandular de- 

 pression on the posterior aspect of the sphenotic process by a narrow 

 isthmus of the general superficies of the cranial vault. 



Each quadrate is a large, powerful bone, built upon the same plan, 

 in so far as its facets are concerned, as we saw in the Fulmar and 

 Petrel. In this Short tailed Albatross, however, it is completely pneu- 

 matic, and a large foramen opens upon its posterior aspect. 



Extremely interesting are the osseous openings to the internal ear, and 

 the deep pit to the inner side of the mastoidal head of the quadrate, which 

 would well repay thorough comparison with similar formations in the 

 skull of the Sula. 



A triangular, bony wiug protects the foramen ovale in front, and 

 a pneumatic foramen may pierce the skull in its neighborhood. 



Viewed from above, we are enabled to see the furrows leading for- 

 ward from the external narial apertures, the broad convexity between 

 these latter and the craniofacial region, where we can still see the 

 traces of the nasal processes of the premaxillary. 



Laterally are the lacrymals, with their sutures plainly visible con- 

 necting them with the naso-frontal margins. 



Posterior to these we have the most striking features of this aspect 

 of the skull; these are the supraorbital glandular depressions. 



I know of no bird where these are better marked than in this Alba- 

 tross, they being profoundly excavated and of a definite reuiform out- 

 line. Their convex surfaces are opposite each other, and separated by 

 a fronto- median tract of some width. Each base is deficient in bone 

 for a little less than its anterior half, while behind they bear the im- 

 press of the convolutions of the glands they lodge in life, and are per- 

 forated by a few small foramina. 



To the rear of these pits the vault of the skull is broadly convex and 

 presents at either side the upper views of the post-frontals and crota- 

 phyte fossae. 



In the skull of an undetermined species of Albatross (No. 1G738 of the 

 List) I notice that quite a perfect septum narium exists; a platform of 

 bone extending between the lower margins of the external openings of 

 the nostrils forms its base, while the septum is reared in the median 

 line- and has a small perforation in its center. 



This specimen has also a broad front to its mesethmoid, which termi- 

 nates in a transverse line at the craniofacial hinge. Just beyond this 

 a thin, triangular plate of bone is applied. The base of the triangle is 

 also in the line of the cranio-facial hinge, though separated from the 

 mesethmoid. Anteriorly its apex is produced to merge into the septum 



