r.A RENTID.E—CIDA RIA. 269 



are often a little less broad ; the central I)aud is usually dull 

 black or black and tawny mingled ; and the tawny baud 

 beyond it narrow, the whole a mixture of these two colours 

 and of white spots and dots of a ]>ecidiarly bright and lively 

 character. It is curious that although this strain is plenti- 

 ful on the hills, the more onliuary varieties are found 

 commonly on the lower ground and the coast. In the 

 Orkneys — where the ordinary range of varieties is found — 

 there is also one in which the general surface of the wings is 

 tawny-yellow, and the central band pale tawny-brown. Soinc 

 peculiar influence of the climate of liigli hills is in some 

 degree exemplified in those of the English iMidlands and the 

 north of Ireland, where often the central baud is of asjjeciallv 

 broad and deep black. 



As may readily be supposed, some of the more striking of 

 these varities were at one time looked upon as distinct species; 

 thus the form in which the central band is broadly white or 

 greyish-white is called ccnUiin-noUdu ; that in which the white 

 was confined to the middle area of the baud roiiciiinata ; that 

 in which the middle of the wing is tavvuy-yellow roiama- 

 notatd ; where the central baud is dusky grey-brown, and the 

 brown colour has spread over the outer tawny band satuvHtu ; 

 and where the central band is black or nearly so prrfuxruta ; 

 l>ut the abuntlunce of intermediatr fdrnis I'ciulers these uames 

 of little value even for varietal purposes. 



On the wing in J\Iay and -lune, and in a second generation 

 in August, Septen)ber. and even October occasionally ; in 

 veiy mild or warm districts a casual and partial third 

 generation may sometimes be found. L have observed it 

 myself in December in Pembrokeshire. 



Larva rather long and slender; the head round but 

 flattened above ; the anterior segments a good deal wriid<lcd ; 

 the s[)iracular liuc puckeied aud prujecliug, thus giving the 

 ■whole larva a I'ather flattened a[)i)e:irancc ; the two anal 

 jjoints acute ; ground colour varying from yellowish-green to 



