THE YOUNG NATURALIST. 



205 



remarkable." Even those males that still 

 retain the silvery hue of the normal form 

 are instantly recognisable by the darker 

 fringe and an indefinable darker shade most 

 noticeable at the veins of the wings. The 

 next change is the appearance of the mark- 

 ings of the female, which are generally brown 

 on the white males and both pink and red 

 on the yellow ones. Some specimens have 

 these markings very distinct, and many have 

 the hind wings smoky. A specimen with 

 dark fore wings is figured in a plate of 

 varieties of the species in the Entomologist 

 for 1880. Mr. J. Jenner Weir, in that 

 magazine, says, " I did not find one instance 

 among the females where the silvery colour 

 usual in the males existed ; but some of the 

 very large silvery males with the thorax 

 buff-coloured might easily have been mis- 

 taken for females." Possibly Dr. Knaggs 

 made a mistake at first by taking some of 

 these examples for the opposite sex. The 

 most marked peculiarity in the females 

 figured on this plate is that the hind wings 

 of some of them shade off to reddish at the 

 hind margin. These Shetland forms are 

 known as the variety Hethlandica. Stdr. 

 This variety is said by Kirby to occur in 

 Holland as well as the Shetland Isles, and 

 if this be so it seems to militate against the 

 suggestions made above. 



Velleda, Esp., The Northern Swift. — 

 Velleda adopts a very different mode of 

 flight to TiumuU, but perhaps equally dis- 

 tinct. It flies with considerable rapidity in 

 a jerky sort of way, just below the top of the 

 grass or herbage, buzzing along for a little 

 distance in a straight line, turning suddenly 

 and flying off at a tangent, as if it had flown 

 against a hard surface, and rebounded, on 

 again for a few yards, then off again at 

 another angle. All this is accomplished at 

 a tolerably regular distance from the ground, 

 the insect not rising or falling in its course. 

 I have no reason but to suppose that the 



male seeks the female in the usual way, for 

 she is much less abundant than her partner, 

 but I have no knowledge on the subject 

 whatever. 



The males of Velleda expand about an 

 inch and half. The forewings are dull 

 reddish brown, with the irregular band 

 already named, and pale spots or streaks all 

 over the wing, very variable in size and 

 number. The hind wings are dull brown in 

 colour, and but thinly scaled. The female 

 is larger, and often expands over two inches, 

 but is dull coloured, and the markings never 

 so well defined. 



The larva and its habits have been well 

 described by Mr. Buckler in Vol. II of 

 the Entomologist's MontTdy Magazine. It is 

 whitish cream in colour, with a pale brown 

 horny plate on the second segment, as in 

 humuli, with additional horny plates 

 on the third and fourth segments, and 

 another on the anal tip. It teeds on the 

 root or rhizome of the common bracken* 

 Pteris aquilina, and when hatched com- 

 mences to burrow by the sides of the stem, 

 eating this as it goes down until it reaches 

 the rhizome. " It continues to feed till 

 quite late in the autumn of the second year, 

 when it becomes full fed ; having, mean- 

 while committed very extensive ravages on 

 the fern. The rhizome, tough as it is, 

 though juicy at the same time, is excavated 

 and channelled out for about the length of 

 ten inches, in some cases nothing being left 

 but the outer rind — in others the galleries of 

 the larva being scooped out tortuously along 

 the outside. The pupa is described in the 

 same article " that of the male being about 

 three quarters, and of the female seven 

 eighths of an inch long, of a uniform reddish 

 brown colour, thick in proportion through- 

 out ; the tip of the abdomen is blunt and 

 rounded, the head slightly beaked, the 

 segments deeply cut ; a very prominent 

 sharp ridge all round the twelfth segment is 

 furnished with short hooks, curved back- 



