278 OSTEOLOGY OF TUBINARES AND STEGANOPODES. 



plane is smooth and but slightly convex, while the outer aspect has a 

 rather spongy interlacement of bony trabecules thrown up against it, 

 developed on the part of the maxillary, prem axillary, and nasal, which 

 most effectively act as its main supports. 



In two of my specimens I find a small, delicate rod of bone attached 

 by ligament to the upper aspect of the palatine body immediately be- 

 neath the ethmoidal wing. These ligaments hold it in an upright po- 

 sition, and its superior and stouter end is beut toward the median 

 plane; from this extremity, also, ligaments are attached which pass to 

 the inferior border of the pars-plana and perhaps across to the descend- 

 ing process of the lacrymal. This little bone I take to be the os uuci- 

 natum of other anatomists, and said by them to occur both in the 

 Albatrosses and Gulls. It seems to play no other part in the bird's 

 economy other than to afford additional support to the membranous 

 wall that forms the lower half of the partition between the orbital cavity 

 and the rhinal chamber. 



As I have elsewhere stated, I have found this bone in but few other 

 birds than this Albatross, one of the specimens of which, Diomedea alba- 

 trus, has it in a very perfect condition on both sides. 



It has been my misfortune, too, not to have seen Professor Bein- 

 hardt's paper upon this subject and his figures showing its position in 

 other birds. Whether the os uncinatum is a constant ossification or 

 not my material is not sufficiently extensive for me to say. 



Professor Parker also states that he has discovered its presence in 

 the Gull, but I have been unable to confirm this, although I have care- 

 fully examined many excellent specimens, with their ligaments still in- 

 tact, of Larus glaucus, L. Philadelphia, Rissa, and others. This is what 

 makes me thiuk that perhaps it may not be a constant ossification, or 

 perhaps occurs only in old birds and not in immature specimens. Forbes 

 says of this ossification that, "in connection with the descending limb 

 of the lacrymal bone, there is often developed a peculiar ossicle, named 

 by Brandt, who was the first to describe its existence, in Diomedea 

 brachyura [albatrns] and Puffinns major, the 'ossiculum lachrymo-pala- 

 tinum,' from its connection with those two bones. 



"Its nature and relations in the group have subsequently been more 

 extensively investigated by Bernhardt, who calls it the 'os crochu.' 



''When best developed, as in the Albatrosses, the ossiculum lacrymo- 

 palatmum is a small styliform ossicle of nearly cylindrical (as in Thai 

 a88iarche culminata [Coll. Scientif. Mem., PI. xxi, Fig. 7]) or somewhat 

 lamellar {Pheebetriafuliginosa [Coll. Scientif. Mem., Pl.xxi, Fig. 8]) shape, 

 attached above by an articulation to the inner face of the descend- 

 ing limb of the lachrymal bone, and below connected by a ligament to 

 the upper surface of the palatine bone. Seen from the side, in the dried 

 skull | his PI. xxn, Fig. I], the bone is visible below the malar arch. It 

 lies, in the recent state, in a cavity between the nose and the roof of 

 the mouth, in an oblique position, pointing downward and inward. This 



