PRELIMINARY CLASSIFIED NOTES 17 



a horsehair or two. (Pis. xx. and 52.) The cock appears to take little or no part in 

 the building. (F. B. K.) Eggs, usually 6 or 7, sometimes 5 and rarely 8, are white 

 in ground-colour and spotted with reddish brown. Sometimes the markings take the 

 form of fine freckles of light chestnut ; at other times the spots are more sparingly 

 distributed and are much darker, showing underlying shell-marks of violet-grey, and 

 a scarce type has big blotches of pale chestnut. (PI. D.) Average size of 100 eggs, 

 60 x -48 in. (15-2 x 12-2 mm.]. Laying begins from the end of April to mid-May 

 according to locality, and incubation, which lasts 12-13 days, is chiefly performed 

 by the hen, but the cock takes her place for part of the afternoon (Naumann). One 

 brood is usually reared, but a small proportion of nests may be found late in the 

 season. [F. c. R. j.] 



5. Food. Insects and their larvae, spiders, and in autumn a few berries, eaten 

 probably when suitable insect food is failing (cf. Newstead, Food of British Birds, 

 p. 24). The young are fed by both parents on insects and their larvee. This species 

 devours a large number of aphides and other injurious insects. [F. B. K.] 



6. Song Period. During the whole of its stay with us, with a period of 

 comparative silence during July. [F. B. K.] 



ARCTIC WILLOW- WARBLER [Phylloscopus trochilus eversmanni 

 (Bonaparte).] 



1. Description. Very closely allied to the ordinary form and not easy to 

 distinguish from it, but generally longer winged, and in spring and summer greyer 

 and less greenish in colour, while in autumn the distinction of colour is less 

 apparent. [F. c. R. j.] 



2. Distribution. This race visits Great Britain only on migration, and breeds 

 in the extreme north of Norway (Finmark), the Archangel Government and North- 

 east Russia as well as in Siberia to the R. Kolyma. Outside its breeding area it 

 occurs in the Balkan peninsula, and Egypt, and apparently ranges in winter to 

 South Africa. [F. c. R. J.] 



3. Migration. See under willow-warbler. 



WOOD- WARBLER [Phylloscopus sibilatrix (Bechstein). Wood-wren, 

 oven-bird, yellow-wren. French, pouillot siffleur ; German, Waldlaubsdnger ; 

 Italian, lui verde.] 



I. Description. Resembling both the chiffchaff and the willow-wren, but 

 larger, and with longer wings, the wood-wren may always be distinguished by the 

 VOL. II. C 



