BUPHAGUS SKUA, THE SKUA. 605 



Stercorarius pomarinus, Vieill., Gal. Ois. ii, 1834, 220, nee Auct. 

 Larus Iceeask, Lath., lud. Oru. ii, 1790, 818. 



b. antarcticiis.* 



Lestris caiarracfes, Quoy et Gaim., Voy. Uran. Ois. 38. 



Stercorarius catarractes, Sciil., Mus. P.-B. iv, 1863, Lari, p. 45. 



Lestris antarcticm, Less., Tr. Oru. 1H31, 60t).— Scl., P. Z. S. 1860, .390.— Abbott, Ibis, 



1861, 16;').— Scl. &. Salv., Ibis, 1869. 284 ; P. Z. S. 1871, 579.— Phil. & Laxdb., 



Cat. Av. Chili, 47.— Hutton, B. N. Z. 1871, 39. 

 Stercorarius aufurcticus,Bv., Cousp. ii, 1856, 207. — Pelz., Oru. Novara, 150. 

 Buphagm u)ilarcticits. Coves, Pr. Pbila. Acad. 1863, 127. 



DiACi. B. maximus, rohustissimns, tarso hreriore digitis mediis cum ungue; rectricibus mediis 

 latis vix ultra cwteras porrectis. Bostri loiigit. 2^ poU. Aug. 



Hah. — Seas and sea-coasts nf tbe Northern Hemisphere, chiefly iu tho more arctic 

 regions. Var. autarcticus, Sonthern seas. 



Adult, breeding plumage. — Bill about as long as or a little shorter than the head, shorter 

 than The tarsus, rcbust, somewhat broader than high at the base, compressed from the 

 middle, its sides bulging : culraen broad, flattened, very slightly concave, or nearly 

 Straight on the ceral portion, the concavity increased by the great convexity of the 

 unguis, which rises higher than tbe ceral portiou ; unguis smooth, broad, rounded, 

 so decurvcd that the apex overhangs the tip of the lower mandible nearly perpendic- 

 ularly. Outline of rami and gouys l)oth slightly concave, the former very long. Emi- 

 ueutia symphysis well marked. Divarication of rami very slight. Tomia of u])per 

 mandible sinuate, at first ascending, then deflected, then again gradually ascending 

 to beyond the nostrils, where it curves sharply downward. Ceral longer than the 

 ungual portion of the bill, its anterior extremity i)rojecting further on the sides than 

 on the culnjeu, so that a <^-sliape(l recess is formed; its inferior edge curving gradu- 

 ally upward from the base, to give passage to the nostrils ; provided at the base with 

 several striic. Nostrils lateral, pervious, somewhat club-shaped, broadest anteriorly; 

 a sulcus on the unguis leads into them from before. Several oblique stritc on the 

 inferior maxilla. Feathers extend on the sides of the superior maudible iu a rather 

 acute angle, leaving a deep recess on the culmen; retreating on the sides of the bill 

 6o nearly parallel with the tomia as to leave the edges of tbe superior maudible ex- 

 posed nearly to the angle of the mouth. Their exteut on the lower madible is less, but 

 is broader, and x\ith a rounded extremity. Between the rami the feathers reach two- 

 thirds the way to tbe symphysis, the remainder being uaked integumeut. Eye of 

 moderate dimensions, placed directly over the angle of the mouth. Wings rather short 

 for the subfamily; the primaries regularly graduated, very broad, with rounded apices ; 

 rachis stiff and strong ; secondaries short, broad, flexible, with broad rounded tips, 

 formed entirely by the inner web. Tertials in the folded wing ending about 3^ inches 

 from apex of first primary. Tail short, broad, strong, even, or nearly so ; tbe feathers 

 rather l)road, with square, almost truncated extremities. Centi'al pair much the same 

 iu shape as tlie lateral ; of e(iual breadth, projecting one or two inches. Superior and 

 inferior tectrices very long and thick, the latter reaching- quite to the end of the tail. 

 Feet large and strong ; the tarsi as long as the middle toe without the claw. Tibiio 

 nude for nearly an inch. That part of the tibia which is bare, the tibio-tarsal articu- 

 lation all around, and the sides and posterior aspects of the tarsus, and both surfaces 

 of the webs, covered with small, irregular polyhedral plates : these plates largest and 

 most regular (being hexagonal) on the sides of the tarsus; very small and numerous 

 ou the webs ; elevated, rough, and conical on the joints and inner snrfaci^s of the toes. 

 Anteriorly the tarsus and toes are covered with imbricated aiutella, regular and 

 transver.se on the toes, but with exceedingly oblicjuc edges on the tarsus, ou the upper 

 third of which they bifurcate into two rows. Toes very long; middle longest ; outer 

 but little less; inner only two-thirds the middle; hallux exceedingly abbreviated. 

 Claws all large, strong, nnicli arched, very acute, the middle one dilated on its inner 

 edge, but not serrated. Membranes long, broad, full, unincised. Dorsal feathers broad, 

 roiuuUd, rigid, closely imbricated, not very thick. Interiorly the ])lumage is exceed- 

 ingly long, thick, conqyact, almost mollipilose. Latero-nnchal feathers elongated, 

 rigid, witli long disconnected iibrilhe. Above blackish-brown, 7nore or less variegated 

 with chestnut uTul AvhitisJi; each feather being dark-colored, with a spot of chestnut 

 towanl its extremity, which in turn fades into whitish along the shaft toward the tip 

 of each feather. Ou the latero-nnchal region and across the throat the chestnut light- 

 ens into a decided reddisli-ytdlow, the white being as a well-delined, narrow, longitud- 

 inal streak on each feather. The crown, post-ocular, and mental region have but littlo 

 whitish. luferiorly the plnmag(! is of a blended fusco-rufous, ligiiler than on the 

 dorsum, with a peculiar indefinite plumbeous shade. The wings and tail are black- 



* The only discrepancy I find, in oxamiuatiou of several from Southern seas, ia tbo 

 shorter, stouter, and mori^ obtuse bill. 



