238 CALIDltIS AHENARIA. 



hind toe. It varies so much in colour, that scarcely two 

 individuals can be found precisely alike. The appearance 

 which it presents at various seasons may be thus described: — 



Male in Winter. — Bill black, iris dusky, feet greenish- 

 black. The upper part of the head, the hind part and 

 sides of the neck and the back, pale grey, each feather with 

 a darker medial streak. The forehead, cheeks, fore part of 

 the neck, and all the under parts pure white. The small 

 coverts margining the wing, the alula, primary coverts, and 

 primary quills are greyish-black ; the secondary quills paler, 

 as are their coverts ; the inner secondaries and the middle 

 coverts light grey. The primary and secondary coverts are 

 tipped with Avhite ; a great portion of the shafts of all the 

 quills is of that colour, and all the quills are white at the 

 base, the portion so coloured extending from the first pri- 

 mary to the tenth secondary, which is entirely white, or 

 with a slight grey mark. Tail-feathers grey, margined with 

 white, the outer feathers paler. 



Length to end of tail 7f inches ; extent of wings 16 ; bill 

 along the ridge 1, along the edge of lower mandible 1 ; bare 

 part of tibia ^ ; tarsus \± ; second toe -fe, its claw -Jj ; third 

 toe T V, its claw T V ; fourth toe yV, its claw yV ; wing from 

 flexure 5-^ ; tail 2-fe. 



Female in Winter. — The female is similar to the male 

 in colour, but somewhat larger. 



Length 8 inches; extent of wings 16; bill along the 

 ridge 1 ; tarsus 1 ; middle toe yV, its claw yV- 



Variations. — The colour of the upper parts may be 

 greyish-white, pale grey, or pale brownish-grey, with the 

 shaft-streaks narrower or broader, and of a darker or lighter 

 tint. But the principal variations are owing to an intermix- 

 ture of new and old feathers, there being a constant succes- 

 sion, and the full winter plumage not being obtained until 

 the middle or end of November. 



Male in Summer. — The bare parts as in winter. The 



