32 PROCEEDINGS OF THE ACADEM1 OP 



But a single species of this genus is known ; which in size vastly exceeds 

 all other Procellarince, and is only itself surpassed by the Diomedince. 



Ossifraga gigantea (6m.) Reich. 



Procellaria gigantea, Gmelin, Syst. Nat. i. 1788, p. 563. Lawrence, Birds N. A. 



1858, p. 825, et al. auct. 

 Ossifraga gigantea, Reichenbach, Syst. At. t. 20, fig. 332. Bonaparte, Consp. 



Av. 1855, ii. p. 186. 

 ? Procellaria brasiliana, Latham, Ind. Orn. ii. 1790, p. 821, No. 2. Gm. S. N. 



i. 178, p. 564. 

 Procellaria ossifraga, Forster, Descr. Anim Ed. Licht., 1844, p. 343. 

 " Quebranthuesos ; '' " Bonebreaker." Vdlgo. 

 Habitat. Chiefly the Southern Seas. Has been taken off the Coast of Oregon. 

 Bill exceedingly robust, compressed, higher than broad at the base ; longer 

 than the head, rather longer than the tarsus (chord of the arc of the culmen 

 about equal to the tarsus ;) sulci separating the rostral laminae very distinctly 

 defined. Nasal case very long, more than half the length of the culmen* ; 

 basally exceedingly broad, being nearly as wide as the bill ; narrowing ante- 

 riorly to the small nearly circular apical orifice ; on the upper surface so flattened 

 as to be a little concave ; the median carination strongly marked, though the 

 ridge is rather broad than sharp, and more elevated anteriorly than at the 

 base ; the apex of the case vertically truncated, not emargined. The frontal 

 feathers extend in an obtuse angle a little way upon the root of the case. 

 Uuguis large and strong, its dorsal outline very broad and not sharp ; regularly 

 decurved, its tip rather obtuse. Commissure much sinuated for its whole 

 length. Gape of mouth moderate, the angle of the commissure falling far 

 short of the eye. Outline of lower mandibular runi about straight: angle of 

 gonys obtuse, its dorsal outline straight, ascending. Feathers of the chin ex- 

 tending quite to the symphysis. Feet very large and stout. Tibia? bare for 

 a considerable portion of their extent. Tarsus short, stout, much compressed, 

 reticulated : the plates minute posteriorly and superiorly ; larger and trans- 

 versely very broad on the infero-anterior aspect. Toes very long ; the outer 

 with its claw as long as the middle ; its claw alone shorter than that of the 

 middle toe. Webs full. Hallux a very stout, nearly straight, subcorneal, 

 obtuse claw. Wings short ; not very pointed : when folded falling considerably 

 short of the end of the tail. Tail of moderate length, or rather short for this 

 group ; much graduated ; of 16 instead of as usual 14 feathers. 



Dimensions. Averasing about 3 feet in length by 7 in extent. Bill 3^ 

 to 4 inches. Tarsus 3 \. Middle toe and claw 5| : outer do. about the same ; 

 inner do. 4^. Wing from the carpal joint about 20 inches. 



The species is found in quiie diverse states of plumage. The upper parts are 

 of a varying shade of brown, and more or less mottled with dull white, the 

 edges and tips of many of the feathers being thus colored. Often however there 

 are no traces of this white mottling, and the dorsal plumage is of a uniform 

 sombre fuliginous. The wings and tail seem to be nearly always plain dark 

 brown. In adult birds the under parts, and a portion of the neck in front are 

 white. The amount of this white varies with age ; and young or immature 

 birds have the whole under parts similarly colored with the rest of the body ; 

 though tiie hue is usually rather lighter and duller. The gradations in color 

 between old and young are very gradual ; scarcely any two specimens, not 

 perfectly mature, being found exactly alike. The feet of some specimens are 

 yellowish, more or less obscured by dusky ; of others are uniform fuliginous 

 brownish black. The bill is yellow in all the specimens I have seen. As a re- 

 markable state of plumage which I do not recollect to have seen given, I may in- 

 stance a specimen in the Philadelphia Academy, which is pure white, all over, 



But its length seems liable to Home c msiier.ible variation. I believe it always extends nearly 

 or quite to the root of the ungu.s. 



[ March . 



