white's thrush. 391 



fringes to outer webs and olive-yellow tips ; median wing-coverts 

 mostly brown-black with pale, large olive-yellow tips ; lesser 

 wing-coverts olive-brown Avith very narrow blackish tips and pale 

 subterminal spots. This plumage ajDpears to be acquired by 

 complete moult in Aug. -Sept., but no adults in actual moult have 

 been examined. Summer. — A moult of the body-feathers takes 

 place in March and Aj)ril, at all events in some examples, but 

 insufficient material is available to determine precise extent and 

 regularity of moult. Abrasion both of winter feathers before this 

 moult and of ncAv feathers later in summer makes upper-parts, 

 wings and central tail-feathers much greyer and less olive-brown. 



Nestling. — (Not examined.) 



Juvenile. — Much like adult but with subterminal bands of 

 featheis of upper -parts more yellowish and not so olivaceous ; 

 chin and upper-throat and under tail-coverts buffish-white without 

 any black tips ; rest of under-parts with narrower black tips and 

 deeper orange-buff subterminal bands than in adult ; two central 

 pairs of tail-feathers with yellowish-buff tips. 



First winter. — Like adults except for tips to central tail-feathers, 

 which are as in juvenile. The juvenile body -feat hers, lesser, median 

 and inner greater wing-coverts are moulted in Aug. -Sept., but not 

 rest of greater coverts nor primary -coverts, wing- or tail-feathers. 



Measurements and structure. — ^ wing 155-164 mm., tail 95-108, 

 tarsus 33-38, bill from skull 28-31 (12 measured). $ wing 154-167. 

 Primaries : 1st 4-14 mm. shorter than primary -co verts, 3rd longest, 

 4th sometimes equal but usually 1-2 mm. shorter, 2nd 5-8 shorter, 

 5th 8-10 shorter, 6th 20-25 shorter ; 3rd and 4th clearly, and 5th 

 indistinctly, emarginated outer webs. Secondaries slightly shorter 

 than 10th primary, tips fairly square. Tail rounded laterally, 

 outermost feathers being 10-15 mm. shorter than longest, 14 feathers, 

 tips ending in fine point, especially in juvenile. Bill strong, 

 cul men slightly curved, especially at tip, upj^er mandible larger than 

 lower, with a notch on cutting edges near tip. Nostrils partly 

 covered by membrane but not by feathers. A good many fairly 

 strong rictal and nasal bristles. Frequently filoplumes on nape 

 numerous and jorojecting beyond feathers. 



Soft parts. — Bill brown, with base of lower mandible yellowish ; 

 legs and feet pale yellowish-brown ; iris brown. 

 Characters and allied forms. — T. d. major (Loo Choo Islands) 

 has only 12 tail-feathers and is larger ; T. d. horsfieldi (Java, Lombok) 

 has 14 tail-feathers but is much smaller ; T. d. dauma (Himalayas) 

 has only 12 tail-feathers and is smaller than T. d. aureus ; T. d. 

 socius (Ta-tsien-lu, China) is said to be darker; T. d. ajffinis a,nd 

 angustirostris (both Siam) require further confirmation. Fourteen 

 tail-feathers, golden and black spotted appearance of upper-parts 

 and broad black band under wing distinguish White's from other 

 British Thrushes. 



