Characters same as those given for the Order. Families. a1. Soles very broad; tarsus stout, more or less feathered, and generally shorter than middle toe without claw. b1. Nostril coverings flat or but slightly swollen ... Treronidæ (p. 24) b2. Nostril coverings swollen forming a grape-seed shaped prominence on each side of culmen ... Columbidæ (p. 51) a2. Soles not greatly expanded on sides of toes; tarsus more slender, unfeathered, and longer than middle toe without claw ... Peristeridæ (p. 54) Family TRERONIDÆ. Soles very broad; tarsus stout, more or less feathered; bill stout or large; gape very wide in some; nostril covering flat or somewhat swollen; tail moderate in length, nearly square; medium to large sized species. Subfamilies. a1. Under tail-coverts long, their tips reaching well beyond toes; size generally smaller; length, 340 mm. or less. b1. First primary not attenuated; third primary scooped on middle of inner web, except in Phapitreron which has mostly brown plumage. ... Treroninæ (p. 24) b2. First primary abruptly attenuated, except in Spilotreron which has mostly green plumage; third primary normal ... Ptilopodinæ (p. 36) a2. Under tail-coverts moderate, their tips reaching little if any beyond toes; size generally larger; length, 360 mm. or more ... Muscadivorinæ (p. 42) Subfamily TRERONINÆ. Genera. a1. General color green or greenish yellow; rectrices fourteen, under coverts usually equal to or longer than shortest rectrix; third primary deeply scooped near middle of inner web. b1. Horny nail of bill reaching feathers of forehead ... Treron (p. 25) b2. Horny nail of bill not reaching feathers of forehead. c1. Tail slightly graduated; under tail-coverts broadly streaked, the shafts black ... Sphenocercus (p. 26) c2. Tail square; under tail-coverts not streaked, the shafts of the same color as the webs ... Osmotreron (p. 26) a2. General color brown; rectrices twelve, under coverts shorter than shortest rectrix; third primary not scooped ... Phapitreron (p. 29) Genus TRERON Vieillot, 1816. This genus differs from the other green pigeons in having the horny portion of culmen extending back to frontal feathers; a small naked area around eye; pattern and colors of the plumage very similar to those of Osmotreron axillaris. 11. TRERON NIPALENSIS (Hodgson). THICK-BILLED GREEN PIGEON. Toria nipalensis Hodgson, As. Research (1836), 19, 164, pl. 9. Treron nipalensis Salvadori, Cat. Birds Brit. Mus. (1893), 21, 34; Sharpe, Hand-List (1899), 1, 53; Oates, Cat. Birds' Eggs (1901), 1, 82; McGregor and Worcester, Hand-List (1906), 9. Treron nasica Steere, List Birds and Mams. Steere Exp. (1890), 24. Mindoro (Steere Exp., Bourns & Worcester); Palawan (Steere, Everett, Whitehead, Platen, Steere Exp., Bourns & Worcester, Celestino, White). Nepal to Burma, Malay Peninsula, Siam, Cochin China, Tenasserim, Borneo.