214 AVES: PYGOPODES. XXXI. 



it. Bill not both strongly hooked and cered. 



k. Iliad toe short, decidedly elevated; toes semipalmate; no soft membrane 

 about nostrils; schizognathous ...... GALLING, XXXIX. 



kk. Hind toe little if at all above level of the rest (rarely absent). 

 /. Nostrils opening beneath a soft swollen cere- like membrane; hind 

 claw short; doves ............ COLUMB^E, XL. 



II. Nostrils not opening beneath a swollen membrane or cere. 

 m. Hind claw not longer than the others; mostly desmognathous. 



n. Wings not very long; gape not very wide nor deeply cleft. Feet 

 zygodactyle or syndactyle. (Toes 2 in front, or if 3, then the 

 outer and middle toes connected for at least half their length 

 in our species.) 



o. Tail feathers soft; bill not chisel-like. . . COCCYGES, XLIII. 



oo. Tail feathers stiff and pointed; bill adapted for striking or 



boring .............. PICI, XLIV. 



nn. Wings very long, with 10 primaries (tail of 10 feathers and bill 

 fissirostral, or else secondaries 6 and bill tenuirostral); toes 3 

 in front, 1 behind, the hinder a little elevated. 



MACROCHIRES, XLV. 



mm. Hind claw at least as long as middle claw; toes always 3 in front, 

 1 behind, cleft to the base or with the basal joints only immov- 

 ably coherent ; palate segithognathous. . . PASSERES, XL VI. 



ORDER XXXI. PYGOPODES. (THE DIVING BIRDS.) 



Feet palmate or lobate; tibia feathered, included in the skin 

 nearly to the heel-joint, hence the legs set far back, so that the birds 

 are scarcely able to walk at all on land ; hind toe small and ele- 

 vated, or wanting ; nostrils developed ; bill horny, not lamellate or 

 serrate ; no gular pouch ; palate schizognathous ; wings very short ; 

 tail very short or rudimentary. 



This is apparently not a natural order. Stejneger (following 

 Huxley) unites the Pygopodes, Longipennes and Tubinares in one 

 order, Cecomorphce. He remarks : " The fact is that not only 

 are the gulls very nearly related to the auks, but their affinities 

 with the GrallcB through the plovers are unmistakable. On the 

 other hand, the grebes seem to be only distantly related to the other 

 * Pygopodes ' and the puffins and albatrosses similarly so to the 

 Longipennes or gulls." The Pygopodes are water birds, expert 

 divers, feeding chiefly on fishes, (irvyfj, rump ; irovs, foot.) 



Families of Pygopodes. 



a. Tail feathers wanting; anterior toes lobed, the claws very broad, flat, 



rounded at tip, resembling human nails PODICIPID^E, 124. 



oa. Tail feathers developed, but short. 



b. Toes 4; the hind toe present URINATORID^E, 125. 



bb. Toes 3, the hind toe wanting ALCIDJR, 126. 



