VOL. vil] ERYTHRISM IN EGGS. • 251 



Red-backed Shrike (/>. c. coUurio). — In this species the 

 erythristic t\^es aie quite common, and vary considerably 

 in intensity of colouring. Some British clutches are as 

 deeply coloured as any Continental, but it is curious to 

 note that in Corsica the other types predominate almost 

 to the exclusion of the red form. 



[Waxwing {Ampelis garrulus). — Although John Wolley 

 applied tlie term " salmon coloured " to some eggs of this 

 species, there seems to be no justification for such an 

 expression (see P.Z.S. 1857, p. 56 ; Ibis 1861, p. 101, and 

 Ootheca WoUeyana, I., p. 221).] 



Spotted Flycatcher {Muscicapa s. striata). — Clutches 

 frequently occur in which the greenish ground is almost 

 obscured by heavy red markings. A clutch taken by Clifford 

 Borrer in Noifolk shows no trace of green, and is richly 

 marked with light red on a creamy ground. A similar 

 set is in Mr. Bunyard's collection from Kent. 



Red-breasted Flycatcher (i¥. p. parva). — ^According 

 to Kricheldorff the eggs of this bird are sometimes erythristic. 



[Cetti's Warbler {Cettia c. cetti). — The eggs are invariabty 

 of some shade of red, generally dark, but there is no tendenc}^ 

 to any other colouring, so that they hardly come ^\ithin 

 the scope of the present paper.]* 



Marsh - Warbler {Acrocephalus pahistris). — The only 

 known instance of erythrism in tlie eggs of this species 

 is a beautiful red clutch of German oiigin, which is now 

 in the museum of Dr. A. Koenig, at Bonn (F.C.R.J.). 



Blyth's Reed- Warbler (A. dumetorum). — These are 

 variable eggs, some being marked with pinkish-brown and 

 violet on a pink ground, or with fine reddish specks on 

 white. The British Museum contains distinctly red 

 specimens from the Altai and Krasnoyarsk. 



Sedge- Warbler {A. schoenobcenus). — A pink variety 

 occurs rarely : the Bidwell collection contained two eggs 

 from Carlisle, taken by T. Duckworth ; Mr. J. Young took 

 a clutch in Scotland {Ann. Scott. Nat. Hist. 1901, p. 49), 

 and Mr. R, H. Read found another near Glasgow ; a fourth 

 set formed part of Mr. L. Field's collection, and a fifth 

 was found in the Esk Valley in 1892 {Birds of Yorks., I., 

 p. 93). 



[Garden- Warbler {Sylvia borin). — There is a red egg 

 in the British Museum from Berkshire, but it is an old 



* A distinctly erythristic type not uncommonly occurs in the 

 eggs of the River-Warbler {Lociistella fluviatilis). 



