BIRDS OF NORTH AND MIDDLE AMERICA. 25 
Limicole with supraorbital grooves and occipital foramina pres- 
ent; coracoids separated; hallux (if present) small and elevated, 
often absent; anterior toes and claws of moderate length or rela- 
tively short, and rectices, 12 or more. 
KEY TO THE FAMILIES OF CHARADRII. 
a, Bill either much shorter than head or relatively stout (never subulate), more or 
less compressed, usually more or less swollen distally anterior to the more or less 
constricted middle or subbasal portion, or if not thus swollen and constricted 
the bill subcuneate in lateral profile (Arenariide); nasal fossee rounded and 
relatively broad at anterior end. 
b. Bill much longer than tarsus, excessively compressed distally, much deeper 
than wide throughout, deepest in middle or posterior to the middle portion, 
the upper and lower outlines converging subbasally; tip of both maxilla 
and mandible broad (rounded or subtruncate) in lateral profile; gonys more 
than twice as long as mandibular rami. (Thigh-muscle formula ABXY.) 
Heomatopodides (p. 26). 
bb. Bill shorter than tarsus, not distinctly (if at all) compressed distally, not much 
deeper than wide, deepest either anterior to middle portion or (in Arenariidz) 
at extreme base, the upper and lower outlines converging for basal half or 
more or (in Arenariide) not at all converging; gonys not twice as long as 
mandibular rami. 
c. Hallux well developed (as long as basal phalanx of outer toe); acrotarsium 
distinctly and regularly transversely scutellate. 
d, Bill subcuneate in lateral profile (not swollen terminally nor contracted in 
middle portion); planta tarsi transversely scutellate; toes more slender, 
without distinct lateral pads; tail slightly rounded. (Thigh-muscle 
formula ARGV) aarscrsic-yictsicictarsreiancrsiararaveisroiwiarel male. qeiseiaina Arenariidee (p. 42) 
dd. Bill plover-like (swollen terminally, contracted in middle portion); planta 
tarsi reticulate (covered with small roundish or hexagonal scales); toes 
stouter, with conspicuous tumid lateral pads; tail emarginate. (Thigh- 
muscle formula ——?)...........-.eeeeee eee ee eens Aphrizidee (p. 57). 
cc. Hallux usually absent, if present very small (much shorter than basal phalanx 
of outer toe), acrotarsium not regularly transversely scutellate, usually 
reticulate, or covered with rather small hexagonal scales. (Thigh-muscle 
formula AB XY,))ccussmeesecssecaseanmeteceemeneuea Charadriide (p. 61). 
aa. Bill variable as to length but not swollen distally, not contracted in middle or 
subbasally, not cuneate in lateral profile; nasal fosse narrow and pointed at 
anterior end. 
6. Tarsus less than twice as long as middle toe with claw, the acrotarsium (usually 
planta tarsi also)¢ regularly transversely scutellate; naked portion of tibia 
shorter than middle toe with claw (whole of tibia sometimes feathered). 
ce. Toes without a distinct lateral membrane; tarsus not unusually compressed; 
plumage of under parts not dense (gull-like)......... Scolopacide (p. 148). 
cc, Toes with a conspicuous lateral membrane, sometimes developed into broad 
scalloped lobes; tarsus excessively compressed; plumage of under parts 
very dense, gull-like...........22.22-.002.00005- Phalaropodide (p. 416). 
bb. Tarsus more than twice as long as middle toe with claw, wholly reticulate 
-(covered all round with small hexagonal scales); bare portion of tibia much 
longer than middle toe with claw. (Plumage of under parts as in Phalar- 
OpPOdide) ovs.0cesswcnwarceaereoseeseueweesexeeees Recurvirostridz (p. 435) 
@ The only exceptions to the transversely scutellate planta tarsi are the genera 
Numenius, Pheopus and Mesoscolopax (part.) 
