Scvert:;off's 'Fauna of Turkestan.' 338 



been described as the young of the former, which, from what 

 I can see, is wrong ; for I have examined over 200 specimens 

 of both species in every stage of plumage, and find that the 

 differences do not depend on age. I may give the diagnoses 

 of these two species as follows : — 



" A. Turdus atrigularis ^ ad. Entire upper parts olive - 

 brown, marked on the crown and back with dark spots ; wings 

 and tail dark brown ; throat, cheeks, and breast black, the 

 feathers having narrow greyish margins in the autumn ; flanks 

 olive-grey, underparts otherwise white; under tail-coverts 

 brown ; under wing-coverts marked with greyish yellow ; adult 

 but not old birds have blackish grey stripes on the sides of 

 the throat, breast, and flanks, but these disappear after the 

 second moult, first on the throat and breast, and then else- 

 where ; legs greyish brown, claws blackish ; maxilla brown, 

 lower mandible yellow, tipped with dark brown. The old fe- 

 male differs in not having the throat black, but blackish brown, 

 with broad yellowish margins, which do not disappear in the 

 spring ; otherwise she resembles the male. The young of both 

 sexes have the throat as in the female ; but the margins to the 

 feathers are broader, giving a pied appearance; the under 

 Aving-coverts are similarly coloured, but are marked with 

 olive-grey lines ; the under mandible is greyish brown, slightly 

 marked with yellow at the base. 



'' B. Tardus mystacinus difl'ers in the coloration of the 

 throat, and both sexes at all ages have this part pied with 

 greyish-brown, blackish, or brownish spots, which sometimes 

 are almost absent in old females, except in the centre of the 

 breast ; on the sides of the throat there are two or three lines 

 of feathers marked with broad blackish spots ; across the 

 breast is a greyish band spotted with black, these spots being 

 larger in the males, w^hich have the throat and breast altogether 

 more boldly marked ; but these diff'erences in the sexes are not 

 constant. The throat does not change in colour as the bird 

 gets older ; but the spots on the breast gradually disappear, 

 and the lower mandible also becomes yellow as in T. atri- 

 gularis. Some of the young females have a dark throat, like 

 old males, and some have signs of a light spot on the throat. 



