1SS . SYLVI1DJK. 



Genus TRIBURA. Hodgg. 



Tribura thoracica (Blyih). 



(Plate IX. figs. 5 & 8.) 



Dumeticola atfinis, Tacz. J.f. O. 1872, p. 354. 



Dumeticola thoracica, Tacz. J.f. O. 1873, taf. i. fig. 3; id. Faune Orn. 



Siber. Orient, p. 250 (1891); Pleske in Prjev. JReisen, Vby. pi. v. 



fig. 7 (1889-94) ; Hartert, Nov. Zool. i. p. 671 (1894). 

 Lusciniola thoracica, Seebohm, Cat. Birds B.M. v. p. 124 (1881) ; Nehrk. 



Kat. Mersamml. p. 33 (1899). 

 Tribura thoracica, Oates, Fauna Brit. Ind., Birds, i. p. 363 (1889) ; id. 



ed. Hume, Nests 8f Eyyslnd. Birds, i.p. 229 (1889) ; Sharpe, Hand-l. 



iv. p. 190 (1903). 



We provisionally follow Taczanowski in uniting the Spotted Bush- 

 Warblers of Lake Baikal aud Sikhirn. He has, however, pointed 

 out that there are important differences between them, and this is 

 confirmed by an examination of the eggs of the birds from the two 

 localities above mentioned. 



The eggs of the Sikhira bird are of a broad oval shape and glossy. 

 They are white or faint pinkish white, speckled and spotted all over 

 with brownish red and lavender, the markings forming a slight cap 

 or zone at the broad end. Five examples measure from '68 to *7 in 

 length, and from '53 to -56 in breadth. 



Eggs from Lake Baikal are of a regular oval shape and but 

 slightly glossy. They are of a pure white colour, speckled and 

 spotted with umber-brown, brownish purple, and lavender. In two 

 specimens the markings are dense at the broad end, but do not 

 form a noticeable cap. In a third specimen they form a wide and 

 confluent zone round the broad end, and are very sparse elsewhere. 

 Three examples measure respectively : - 71 by "55; "71 by '53; '71 

 by -53. 



The differences between the eggs of the birds from the two 

 localities arc very marked, much more so than might be gathered 

 from the descriptions alone. 



1. Native Sikhim, 15th July (L. Hume Coll. 



Mandelli). 



1. Native Sikhim, 17th July (L. M.). Hume Coll. 



1. Native Sikhim, 21st July (L. M.). Hume Coll. 



2. Rungbee, Darjiling, 6000 ft., 5th Hume Coll. 



June (./. Gammie). 

 ^. Lake Baikal, Siberia {Dybotoski). Seebohm Coll. 



2. Lake Baikal (Dybowski: Tristram Crowley Bequest. 



Coll.). 



