127. Numenius (Curlew, Whimbrel). Bill much larger than the head, slender, curved downwards.
ORDER GAVIÆ
Front toes entirely connected by webs. Primaries, ten large and visible, one minute and concealed.
FAMILY LARIDÆ
(Gulls, Terns, Skuas)
SUB-FAMILY STERNINÆ
Bill straight, rather slender; mandibles of about equal length.
128. Hydrochelidon (Black, White-winged, and Whiskered Terns). Tail feathers rounded or slightly pointed; tail short, less than half length of wing.