218 AVES : LONGIPENNES. XXXII. 



W. 8J. T. 3}. B. 1}. K Atl., S. to Conn. (Eu.) (An old 

 name.) 



326. PLAUTUS Briinnich. (TrXws, swimmer.) 



640. P, impennis (L.). GREAT AUK. Black above; lower 

 parts and tips of secondaries white. L. 29. W. 5|. B. 3. N. 

 Atl., formerly S. to Mass.; now wholly extinct. " His GRACE, the 

 AUK, who lost the use of his wings, and perished off the earth in 

 consequence." (Cowes.) (Lat., wingless.) 



327. ALLE Link. (Swedish name.) 



641. A. alle (L.). DOVEKIE. Upper parts black, the second- 

 aries tipped with white ; sooty-brown in summer. L. 8. W. 4f . 

 B. J. Arctic, S. to N. J. (w.) 



ORDER XXXII. J^ONGIPENNES. (THE LONG-WINGED 



SWIMMERS.) 



Feet palmate ; tibia feathered ; legs inserted near the centre of 

 equilibrium so that the bird stands with the axis of the body nearly 

 horizontal ; hind toe small and elevated, sometimes wanting. Bill 

 usually long, horny, not serrate nor lamellate ; nostrils developed, not 

 tubular ; no gular pouch. Wings very long and pointed ; tail well 

 developed. Palate schizognathous. Altricial. Water birds, of 

 great powers of flight, feeding chiefly on fishes, 

 a. Bill with the lower mandible not produced nor specially compressed. 

 b. Covering of upper mandible in three parts, a hook at tip, a sort of cere 

 overhanging nostrils, and a lateral piece. . . STERCORARIID^E, 127. 

 bb. Covering of upper mandible of a single piece pierced by the nostrils. 



LARID.E, 128. 



aa. Bill with the lower mandible much longer than upper, the terminal part 

 of both mandibles much compressed, like a knife-blade. 



RHYNCHOPID.E, 129. 



FAMILY CXXVH. STBBCORARIID^. (THE J^GERS.) 



Gull-like birds, with the bill hooked and " cered ; " tail square, 

 with the middle pair of feathers long-exserted ; tibia naked below ; 

 tarsus scutellate in front, granular behind. Two genera with 4 

 species, " marine Raptores," large, vigorous, rapacious, living by 

 robbing the terns and smaller gulls. 



a. Depth of bill at base at least half length of upper mandible (measured along 

 side); tarsus shorter than middle toe and claw; tail short, nearly even. 



MEGALKSTRIS, 328. 



aa. Depth of bill at base not half length of upper mandible; tarsus longer 

 than middle toe and claw ; middle tail feathers (in adult) very long. 



STERCORARIUS, 329. 



328. MEGALESTRIS Bonaparte, (pcyas, large ; Xgorpfr, pirate.) 



642. M. skua (Briinnich). SKUA GULL. Grayish-brown, L. 

 22. W. 16. B. 2. N. Atl., rarely S. to Mass. (Eu.) (Faeroese 

 name.) 



