ARTIFICIAL KEY TO THE FAMILIES. 231 



ARTIFICIAL KEY TO THE FAMILIES. 



TOES 3, — 2 IN FRONT, 1 BEHIND PlCID^ 477 



TOES 3, — 3 IN FRONT. (Go to II.) 



TOES 4,-2 IN FRONT, 2 BEHIND. (Go tO III.) 

 TOES 4, —3 IN FRONT, 1 BEHIND. (Go tO IV.) 



II. [Toes 3, — 3 in front.] 



Toes — completely webbed. Nostrils — tubular (Albatrosses) Procellariid.*: 773 



— not tubular (Auks, fee.) Aloid^ 797 



— incompletely or not webbed. Legs — about as long as wings. Bill subulate (Stilt) Recttrvirostrid.*; 609 



— much shorter than wings (go to a). 



,a) Tarsus — scutellate in front, about as long as bill (Sanderling) ScOLOPACiDiE 614 



— reticulate in front — shorter than red chisel-like bill (Oyster-catcher) . H^matopodid.e 606 



— longer than bill (Plovers) CHARADRiiD.ffi 597 



III. [Toes 4, — 2 in front, 2 behind.] 



Bill — cered and strongly hooked. Tarsus granulated (Parrot) Psittacid.*: 496 



— not cered; inner hind toe — 3-jointed; Plumage iridescent (Trogon) Trogonid.«; 468- 



— 2-jointed ; — tail of — 8 or 10 soft feathers (Cuckoos, &c. ) . . Cucdlidje 470 

 — 12 (apparently only 10) rigid acuminate feathers 



(Woodpeckers) PiciD.® 477 



IV. [Toes 4, — 3 in front, 1 behind.] 



Hind toe — inserted above the level of the rest (and always shorter than the shortest 

 front toe). (Go to A.) 

 — not inserted above the level of the rest (and generally but not always not 

 shorter than the shortest front toe). (Go to B.) 



A, \The hind toe elevated. \ 

 Feet — totipalmate (all 4 toes webbed; hind toe semv-lateral and barely elevated). (Go to A.) 



— palmate [Z front toes full-webbed, hind toe well up, simple or lobed or connected by slight webbing to 



base only of inner toe). (Go to B.) 



— LOB ate (3 front toes partly webbed or not, and conspicuously bordered with plain or scalloped mem- 



branes ; hind toe free, and simple or lobed). (Go, to C.) 



— semipalmate (2, or Z, front toes webbed at base only by small yet evident membrane ; hind toe well up, 



simple). (Go to D.) 



— simple (front toes with no evident membranes : hind toe veil tip, simple). (Go to E.) 



(A.) Tarsus — feathered, partly ; tail deeply forked; bill epigiiathous Frigate-bird) .... Tachypetid.*: 730 

 — naked; bill — > tail, hooked at tip, furnished with enormous pouch (Pelicans) Pelecanid.e 721 

 — < tail; throat — feathered; middle tail feathers filamentous (Tropic-birds) 



Phaethontid.*; 731 

 — naked; tail — pointed, soft; tomia8ubserrate(Gannets)SiTLiDiE 720 

 — rounded, stiflf; bill — paragnathous (Anhinga) 



PLOTID.E 729 

 — epignathous (Cormorants) 



PHALACROCOKACIDiE 723 



