THE YOUNG NATURALIST. 



337 



BRITISH BUTTERFLIES. 



By J. E. Robsox ; with figures from life by 

 S. L. Mosley. 

 (Assisted by Contributors to the Y.N.) 



ARION, L. PI. 24, Fig. 4. 

 The Large Blue. 

 "Arion, L., Ari'on, a celebrated Lyric 

 Poet, Cf., Her. i. 23.— A.L. 



ImagO. — PI. 24, Fig. 4. Deep dark blue, 

 hind margin black; there is a black cen- 

 tral SPOT ON THE FOREWING AND FOUR OR 

 MORE WEDGE-SHAPED SPOTS BETWEEN IT 



and the hind margin. The hind wing is 

 scarcely so blue as the forewing, and there 

 is sometimes a row of black spots similar 

 to those on the forewing, but more fre- 

 quently there are only faint traces of them. 

 Underside silvery grey, with a blue tinge 

 near the base ; the black spots are large 

 with white rings ; there are none nearer the 

 base than the disc spot, and there is a double 

 row round the hind margin. There are no 

 orange spots at the hind margin. 



Larva. — When eleven days old, Mr. 

 Porritt, of Huddersfield, thus describes the 

 larva ol Arion. " Length about one-sixth of 

 an inch ; stout, but tapering towards the 

 head, which is much smaller than the second 

 segment ; the general colour was dirty pink, 

 the head brown and shiny ; behind the head 

 is a large, almost plate like, dull black mark, 

 from which extends the rather broad con- 

 spicuous rust-coloured dorsal line; the body 

 is sparingly clothed with light brown hair." 



Pupa. — I know of no description. 



Food Plant. — Wild Thyme (Thymus 

 serpyllum). Mr. Porritt's larva would have 

 appear to eaten the flower at first, though it 

 stretched itself along the midrib of a leaf 

 when about to moult. 



Times of Appearance. — The butter- 

 fly appears in average seasons about the 

 second week in June, and continues to 

 emerge for three or four weeks. In forward 

 seasons it has been taken as early as the 6th 

 June. The larvae hatch early in July, and 



I there my knowledge of it ends. Newman 

 says that Mr. Porritt's larvae hatched on 

 4th May, but this is a blunder and should 

 be 4th July, as a reference to the original 

 passage will show. 



Habitat. — In England this butterfly is 

 both rare and local. It appears to be most 

 abundant in Devonshire, Gloucestershire, 

 Northamptonshire, and Somersetshire, and 

 has occurred or is still found in Bedford- 

 shire, Buckinghamshire, Dorsetshire (once), 

 Hampshire, Herefordshire, Huntingdon- 

 shire, and Wiltshire. It does not occur in 

 any other portion of the British Isles. It is 

 found all over Europe, except in the extreme 

 north, and in Northern and Western Asia. 



Variation. — A variety called Alcon, by 

 Stephens, is not very rare in collections. It 

 is generally smaller than the type, and is 

 without the black spots on the forewing, 

 except that at the disc. The spots on both 

 the upper and under sides vary in number 

 and size. An underside, from a specimen 

 in Mr. Bond's collection, is figured in New- 

 man, in which they are extra large and 

 numerous. Another form is named Cyanecula 

 Eversm., from North-eastern Siberia. 



Genus III. Thecla, Fab. 



"Thecla, F., Thec'la, Virgin and Martyr. 

 Cf. Butler's Lives of the Saints, ix., 286." — 

 A.L. 



Thecla is a genus of which between five 

 and six hundred species are now described. 

 Its head quarters appear to be America.where 

 more than nine-tenths of the species occur. 

 A few are found in Asia and Africa. Nine 

 or ten in Europe, of which five are British. 

 Most of the species are tailed. Many of 

 them have one or more fine lines across the 

 underside of both wings, whence the com- 

 mon name " hair streak." A curious char- 

 acteristic of the genus is that the members 

 of one sex, generally the male, often have a 

 " satin or plush-like patch on the forewings 

 at the extremity of the discoidal cell." 



The five British species may be distin- 

 guished as follows : — 



