INTRODUCTION. xix 



luin connucnt witli its keel. Carotids douljje. Palate highly desmogna- 

 thous. Reproduction aliricial; young psilopiedic or ptilop<edic. Eggs 

 threap or fewer. 



Li. LONGIPENNES. (To mo.st of the characters of the group here given 

 the genus Ilalndroma is a signal exception, though unquestionably belong- 

 ing here.) Feet palmate. Tibia; feathered. Legs at or near centre of equi- 

 librium, affording horizontal position of axis of body in walking. Knee 

 scarcely buried in common integument; tibia sometimes with a long apo- 

 physis. Hallux elevated, free, functionless ; very small, rudimentary, or 

 wanting. Rostrum of variable shape, usually compressed and straight to 

 the hooked end, sometimes entirely straight and acute, commonly length- 

 ened, always corneous, without serration or true lamellae. Nostrils of vari- 

 ous forms, tubular or simply fissured, never abortive. No gular pouch. 

 Wings very long and pointed, surpassing the base and often the end of the 

 large, well-formed, few-feathered tail. Carotids double. Palate schizog- 

 nathous. Reproduction altricial ; young ptilopiedic. Eggs three or fewer. 

 Habit highly volueral. 



M, PYGOPODES. Feet palmate or lobate. Tibia; feathered, often with 

 a long apophysis, always buried in counnon integument nearly to the heel- 

 joint, necessitating a more or less erect posture of the body on land, where 

 progression is difficult. Hallux small, elevated or wanting; feet lobate or 

 palmate. Bill of indeterminate shape, wholly corneous, never lamellate or 

 serrate, nor with gular pouch. Nostrils not abortive. Wings very short, 

 reaching scarcely or not to the base, never to the tip, of the .short, some- 

 times rudimentary, tail. Palate schizognathous. Carotid usually double, 

 sometimes single (in Podiceps and Mergulus). Nature altricial or prrecocial; 

 young ptiloprrdir. Highly natatorial. 



fi. SPHENISCI. With general characters of the last group, but dis- 

 tinguished by unique ptilosis and wing-structure, etc. Plumage without 

 apteria, of singularly modified scale-like feathers on most parts ; no devel- 

 oped remiges. Wings unfit for flight, insusceptible of perfect flexion or 

 extension, very short, with peculiarly flattened bones and stable articulations. 

 Skeleton non-pneumatic. Many bones, terete in ordinary birds, here flattened. 

 Metatarsal bone flattened transversely, doubly fenestrate. Hallux elevated, 

 lateral, minute, free. No free pollex. Two anconal sesamoids ; patella 

 from double centres; tibia without apophysis; a free tarsal ossicle. Ster- 

 num with long lateral apophyses. Pelvic connections unstable. Caro- 

 tids double. Comprising only the Penguins. Confined to the Southern 

 Hemisphere. 



Having thus presented and defined an arrangement of the higlier group.s 

 into which recent Carinate birds are susceptible of division, I next proceed 

 to the consideration of the North American Families of birds wliicli the 

 autliors of the present work have provisionally adopted as suitable to 

 the end they had in view. Professor Baird urges the caution that the 

 scheme is intended merely for the convenient determination of the North 

 American species, aware that in many instances diagnoses or antitheses of 

 entire pertinence in such application would fail or be negatived by con- 

 sideration of the e.xotic forms. The arrangement of tlie families here 

 adopted is essentially that presented in 18.38 in Professor Baird's " Birds of 



