Part 139

Mearns gives the following measurements of two males from Basilan: "Length, 240, 255; wing, 215; tail, 75; bill from frontal feathers (chord), 8.5, 9.6; bill from anterior margin of nostril, 6.1, 7.1; tarsus, 19, 20; middle toe with claw, 22.5."

But six specimens of this large swift are known, three from Celebes, one from Negros, and two from Basilan.

322. CHÆTURA DUBIA McGregor.

PHILIPPINE SPINE-TAILED SWIFT.

Chætura dubia McGregor, Bur. Govt. Lab. Manila (1905), 34, 15, pl. 12; McGregor and Worcester, Hand-List (1906), 59.

Mindoro (McGregor).

Adult.--General color blackish brown; back and rump noticeably lighter, being light seal-brown, each feather with a subterminal, more or less concealed area or band of bluish violet; head and body shot with bluish violet gloss, strongest on chin, throat, breast, and sides of head and neck; a large white patch on each side between nostril and lores; crissum white, each feather blackish brown at its base, the long tail-coverts with edges also blackish brown except near tip; extending diagonally upward and forward on each flank, a wide white stripe connected with the white crissum behind as in Chætura gigantea; exposed edges of wing-feathers black, inner webs of primaries largely light brown; inner webs of alula, primary- and secondary-coverts shot with greenish blue gloss; tertiaries greenish blue; lining of wing brown, each feather bordered with dirty white which has its greatest extent on innermost feather; axillars dark brown, shot with bluish violet gloss, exposed portion of tail blackish, the concealed basal portion glossed with green and blue. Bill black; iris brown; legs and feet reddish flesh; nails light brown.

Male: Length, 229; wing, 220; tail, 64; bill from frontal feathers, 10; bill from anterior margin of nostril, 7; tarsus, 18. Female: Length, 234; wing, 218; tail, 64; bill from frontal feathers, 10; bill from anterior margin of nostril, 7; tarsus, 18.

This fine species is known from the type specimens, a pair taken on the Baco River, Mindoro. It requires comparison with Chætura celebensis. The following notes probably refer to Chætura dubia:

"We think it probable that C. gigantea will eventually be found in Mindoro. We repeatedly saw a very large swift in that island, but it always kept well out of range. We thought it to be C. gigantea but could not, of course, be at all sure. On our first trip we found C. gigantea flying low over the mangrove swamps in Palawan and had no special difficulty in securing specimens. On our second trip, however, we were less fortunate, as the few individuals that we saw kept out of range." (Bourns and Worcester MS.)

323. CHÆTURA PICINA Tweeddale.

TWEEDDALE'S SPINE-TAILED SWIFT.

Chætura picina Tweeddale, Proc. Zool. Soc. (1878), 944, pl. 59; Hartert, Cat. Birds Brit. Mus. (1892), 16, 487; Sharpe, Hand-List (1900), 2, 92; McGregor and Worcester, Hand-List (1906), 59.

Leyte (Whitehead); Mindanao (Everett).

Adult.--"Black with a blue gloss, greenish in some lights; chin, throat, and larger under wing-coverts pure white. Wing, 161; tail, 32." (Tweeddale.) "Iris dark brown; bill black; legs lead-gray." (Whitehead.)

This species is known only from the type, a female collected near Zamboanga, Mindanao, and from three specimens taken in Leyte by Whitehead.

Subfamily MICROPODINÆ.

Genera.

a1. Smaller; toes all directed forward, but in pairs, two toes on each side of the median tarsal line; plumage nearly uniform brown. ... Tachornis (p. 360) a2. Larger; toes all directed forward and at equal intervals; chin, throat, and rump white. ... Micropus (p. 361)

Genus TACHORNIS Gosse, 1847.

Toes all directed forward, in pairs, two toes on each side of the median tarsal line, none of them reversible; tail deeply forked, its feathers narrow; plumage nearly uniform in color without white markings.

324. TACHORNIS PALLIDIOR McGregor.

PALER PALM SWIFT.

Tachornis infumatus McGregor, Bull. Philippine Mus. (1903), 1, 5. Tachornis pallidior McGregor, Bur. Govt. Lab. (1904), 25, 27; McGregor and Worcester, Hand-List (1906), 59.

Bohol (McGregor); Cebu (McGregor); Luzon (McGregor); Mindanao (Celestino); Ticao (McGregor).

Adult.--Upper parts dark brown; nearly black on head, neck, and back which have a faint green gloss; feathers of rump and upper tail-coverts lighter brown and narrowly fringed with gray in unworn plumage, the tail-coverts with dark shafts; wing-feathers blackish brown, glossy on outer webs; short primaries narrowly edged with white on inner webs; tail of the same color as wings; sides of head brown; chin and throat light drab-gray, merging gradually into the dark drab-gray of the lower breast and abdomen where the feathers are narrowly edged with whitish; stiff feathers in front of eye white with brown tips. Length in flesh, 114; wing, 119; lateral rectrices, 50; central rectrices, 31.

This species is easily recognized by the deeply-forked tail and peculiar paired toes; it is a near relative of Tachornis infumata from which it differs chiefly in having a paler chin and throat. It has been found in small numbers in the islands from which it is recorded.

Genus MICROPUS Meyer and Wolfe, 1810.