544 MANUAL OF PHILIPPINE BIRDS. 
525. PLANESTICUS THOMASSONI (Seebohm). 
LUZON BLACK THRUSH. 
Merula thomassoni SEEBOHM, ol Brit. Orn. Club (1894), 3, 41; Grant, 
Ibis (1894), 508; (1895), 445; SHARPE, Hand-List (1903), 4, 120; 
McGrecor and WorcEsTER, Hand-Lst (1906), 83. 
Turdus thomassont WHITEHEAD, Ibis (1899), 212. 
Bul-it, Benguet. 
Luzon (Whitehead, McGregor, Mearns). 
Adult.—Entire head, neck all round, chin, throat, and chest light 
smoky brown, darker on forehead and crown; remainder of plumage 
black; some of the feathers at sides of abdomen tipped with white; 
under tail-coverts with white shaft-streaks and narrow rusty brown tips. 
Bill, legs, and nails yellow. Length of a male, plumage somewhat worn, 
240; wing, 116; tail, 92; culmen from base, 22; bill from nostril, 14; 
tarsus, 31. A female, wing, 118; tail, 93; culmen from base, 24; bill 
from nostril, 15; tarsus, 33. Even in adult birds there is some variation 
in the amount of white on the under tail-coverts, and rusty brown fringes 
on the feathers of the abdomen seem to indicate immaturity. A young 
male has the head and neck black instead of chocolate-brown and the 
feathers of lower breast and abdomen are liberally marked with rusty 
brown, this coloring the shafts of some feathers. 
526. PLANESTICUS MAYONENSIS (Mearns). 
MAYON BLACK THRUSH. 
Merula mayonensis MEARNS, Phil. Jour. Sei. (1907), 2, sec. A, 358. 
Luzon (Mearns). 
“Characters.—Pattern of coloration similar to that of Merula thomas- 
sont Grant, but darker, with less contrast between the coloration of the 
head and that of the body. Smaller, with relatively stouter bill; preanal 
feathers not tipped with white. 
“Description of type (adult male).—Upper surface except head and 
neck all black; under surface of body black perceptibly washed with 
brown on feather edges; head and neck very dark brown, almost black 
on crown; entire under surface of wings and tail dull black; under tail- 
coverts black with narrow median white stripes involving the shafts. 
Iris very dark brown; eyelids, bill, feet, and claws all yellow. Female 
exactly like the male. A younger male than the type differs only in 
having the feathers of the under side of the body edged with yellowish 
brown. Length, 215; wing, 120; tail, 101; culmen (chord measured 
from true base), 22; bill from anterior margin of nostril, 13; tarsus, 
34; middle toe with claw, 32.5. 
“Female.—Length, 210; wing, 117; tail, 99; culmen, 20.5; bill from 
nostril, 13; tarsus, 33; middle toe with claw, 32.” (Mearns.) 
