10 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



hh. Sternum keeled ; ^ lumbar vertebrae 15 ; carpals2; furoula present;^ coracoids not 



coalescent with scapulse; iliac bones divergent; wings well developed, used 



for flight (Division Carinatic.*) 



u. Metacarpals united only at extremities; biceps patagii absent; wings destitute 



of remiges, covered' with small horny scale-like feathers, used only as rowing 



paddles Sphenisciformes. 



cc. Metacarpals fused for entire length; biceps patagii present; wings with remiges 

 and otherwise normally feathered, used for flight.^ 

 d. Tibia with long, triangular epicnemial process; aquatic, with well-developed 

 hallux; anterior toes fully webbed or else lobated, with broad, flat nails, 



and rectrices absent; bill compressed and acute Colymbiformes. 



dd. Tibia without epicnemial process; if aquatic, full webbed anterior toes 

 not combined with a well-developed hallux and acute compressed bill, 

 nor lobated toes, with broad, flat nails and absence of rectrices. 

 (-. External nostrils tubular; hallux absent or reduced to a single phalanx; 



anterior toes fully webbed Prooellariiformes. 



ee. External nostrils not tubular, or else hallux present and anterior toes 

 not webbed. 

 /. Ambiens muscle present; deep plantar tendons of Type I, II, III, IV, 

 V, or VII, never of Type VI nor VIII.'' 

 g. Toes not zygodactylous. 

 h. Palate desmognathous.' 



' The keel obsolete or rudimentary in a member of the Cuculiformes (genus Strin- 

 gops, Suborder Psittaci). 



^ Except in Slringops and a few other Psittaci. 



^Not used for flight, though well developed, in Slringops. 



*^l(es Carinatie Merrem, Tent. Syst. Av., 1813, — . — Carinatx Huxley, Proc. Zool. 

 Soc. Lond., 1867, 418. — Xeornithes CarmoteGADow, Bronn'sThier-Reichs,Vog., ii, 1893, 

 119, 299. The EiwrnMes of Stejneger (Soi. Rec, ii, May 15, 1884, 155; Stand. Nat. 

 Hist., iv, 1885, 64) are nearly equivalent, hat the S'phenisciformes and Cn/jiiuriformea 

 are excluded, the latter being referred to the Droinxognathic {=Ratilx^Orypturi- 

 formes). The Dromieognathie of Huxley (Proc. Zool. Soc. Lond., 1867, 456), it may 

 be remarked, included only the Crypturiformes. 



° A few exceptions to the use of the wings for flight are exemplified, in addition to 

 the case of Stringops, already mentioned, in certain large aquatic birds, as the now 

 extinct Great Auk (Flauttis impennis, a member of the Charadriiformes) and Pallas's 

 Cormorant {Pkalacrooora.r pcrxpiciUatus, belonging to the Ciconiiformes); and, among 

 existing birds, the large cormorant of the Galapagos Archipelago (Phalaa-ocorax 

 harrisi) and adults of the Steamer Duck ( Tachyeres cinereus, of the Anseriformes) of the 

 Straits of Magellan. In all these, however, the wings, although normally feathered, 

 are much too small in proportion to admit of flight, their principal function being for 

 propulsion beneath the surface of the water, as in the case of the penguins (Sphenisci- 

 formes) and most diving birds, including even the Passerine genus Cinclus. 



''See Gaerod, Proc. Zool. Soc. Lond., 1875, pp. 339-348; Gadow, Bronn's Thier- 

 Keichs, Vogel, ii, 1893, pp. 224, 225, footnote, and in Newton'.s Dictionary of Birds, 1894, 

 pp. 615-618. The numeration of types here used corresponds with that of the Thier- 

 Eeichs and of the text in the Dictionary of Birds, but not of the figures on page 617 of 

 the latter, where eleven instead of eight types are shown. 



'For definitions of the terms desmognathous, schizognathovs, xgillmgnallioiis, and 

 dromseognathous, frequently employed in the present key, the reader is referred to the 

 important paper, by Prof. T. H. Huxley, On the Classification of Birds, and on the 

 taxonomic value of the modifications of certain cranial bones observable in that 

 Class (Proc. Zool. Soc. Lond., 1867, pp. 415-472). 



