62 KEY TO THE GENEKA. 



IV. [Toes i, — 3 in riiosx, 1 behind.] 



§. Hind toe insehted above the level of the rest (and always shobtek than the shohtest 

 anterior toe). (a) 

 §. Hind toe not inserted above the level oi^' the rest (and generally hut not always not shorter 



THAN THE, SHORTEST ANTERIOR TOE). (B) 



A. {The hijid toe elevated.) 



1. JTeet TOTIPALIIATE; (all 4 toes wehhed ; hind foe semilateral and barely elevated.) (A) 



2. J^eet balsiate; (3 front toes completely wehhed, hind toe well up, simple or lobed, free or connected hy 

 slight webbing with base only of inner toe.) (B) 



3. Fe£t lobate; (.3 front toes {partly webbed, or not, and) CONSPICUOUSLY bordered with 2^lain or scolloped 

 membranes ; hind toe free, and simple or lohed.) (C) 



4. Feet sejhbaljiate; (2, or Z, front toes webbed at base only by small yet evident membrane ; hind toe jvell 

 up, simple.) (D) 



.5. Feet simple; front toes with no evident membranes ; hind toe well up, si77iple. (E) 



(A) Tarsus featlieretl, partly; tail deeply forked; bill eijignatlious, Tachy'petes 277 



— naked; bill > tail, hooked at tip, furnished witli an enormous pouch, .... Pelecanus 274 



— < tail; throat feathered; middle tail feathers lilamentous, Phaethon 278 



— naked; tail pointed, soft; tomia siihsen-ate, Sula 273 



- — rounded, fetifl'; bill paragnathous Plotus 276 



— epignathous, Graculus 275 



(B) Hind toe someivhat lateral, and joined by slight web to bate only of inner toe Coltmeus .311 



— directly x^osterior, free, and simple or lobed. (ll) 

 (h) Bill — lecnrved, depressed at base, subulate, extremely acute Recurvirostra 196 



— bent abruptly downward near its middle, and lamellate, Phoenicopterus 246 



— neither recurved, nor abruptly bent, (i) 



(i) Bill — ftT/^ofimrt^/iows, corneous, cultrate, sulcate, Riiyn CHOPS 295 



— paragnathous, corneous, moi lamellate ; nostrils not tulmlar; tail noi oven, (k) 



— epignathous (or paragu. and tl. even), corneous, not lamellate ; nostrils not tubular. (1) 



— epignathous, corneous, not lamellate; nostrils tubular, (m) 



— paragnathous, mostly membranous, lamellate, no.strils not tubular, (n) 



(k) Tail graduated, and middle feathers shorter than next pair. Plumage sombre brown . . . Asous 294 



— forked; toes almost semipalmate. Black, brown or ashy, and white, .... Hvdrochehdon 202 



— well webbed; feet not black; back pale; no crest, Sterna 291 



— blk. ; wht. crescent on forehead (Sterna, 291, or) . Haliplana 293 



— no orescent; not crested; b. barely>trs., Gelochelidon 289 



— crested; b.much>tr8., . Thalasseus 290 

 1) Bill with a sort of cere; middle tail feathers exserted; tarsus <otcl Buphagus 279 



— = 3tcl., Steecorarius 280 



— not cored; land toe rudimentary, not bearing a perfect claw, ElSSA 2S4 



-perfect; tail wedge-shaped; a dark collar round neck, . . Ehodosthethia 286 



— forked; bill black, tipped with yellow, Xema 287 



— reddish, not tipped with yelloM', . . . Creagrus 288 



— even; tarsus black, rough; webs incised Pagophila 285 



— not black. Under plumage — (1=) 



(1=) dark, head white, tail black, bill and feet reddish, . . . . Blasipus 2S2 

 (1=) white, head dark (if dark, head whitish), . . . Chrcecocephaliis 283 



(1=) white, head white (if dark, head not whitish), Larus 281 



(m) Tarsus not < St.; claws depressed, obtuse; tarsal scutella fused ; webs with yellow, . Oceanites 307 



— distinct; Avebs black, .... Fregetta 8C8 

 — compressed; tail cuneate; no white anywhere Halocyptena 303 



— nearly even. Blk. or smoky brown, and white, Pkocellaria 304 



— forked. Blk. or smoky brown, .and white, . Cymochorea 305 



— Not black and white, Oceanodeoma :506 



(m) Trs. <3tcl.; tail of 12 feathers; nasal tube obliquely truncate, septum thick, Puffinus 310 



— vertically truncate, septum thin Priofinus 309 



— >12fthrs.; plnig. conspicuously sijotted, Uaption 301 



-unspotted; tl. cuneate Aestkelata 302 



— notcuneate; 18-fthr'd, Ossifraga 298 



— 11-fthrd. b.<trs., Fulmarus 299 



— = trs., Priooella liOO 



(n) Lamellre acute, like saw-teeth, retrorse; bill terete, blaek; trs. = J 3t Lophodytes 272 



— not black; trs. >i:tt., Mergus 271 



— simple; bill depressed toward end; lores nakoil. Adult entirely white Cygnus 247 



— feathered; trs. in front— reticulate, (o) 



— scutellate. (p) 

 (o) Trs. not>3tri. I'lumage partly lavender-colored, head white, throat black, Philacte 249 



— =-3tcl.; bill and legs not black. White or gray, bluish, speckled, etc Anser 248 



— black; neck all black: nostrils median, Branta 250 



— not all black; uostrila subbasal, . . . Dendeocvqna 251 



