PLATE XXI. 
No. 1.—The Brown Hair-streak Butterfly (Thecla No, 9.—The Caterpillar of the Dark Hair-streak 
Betule). Butterfly. 
No. 2.—The Female of the Brown Hair-streak But- No. 10.—The Chrysalis of the Dark Hair-streak 
of ee ee ‘ ; ; Butterfly. 
2 ety ee ore irate No. 11.—The Black Hair-streak Butterfly (Thecla 1. 
No. 4.—The Caterpillar of the Brown Hair-streak s avn . 
Butterfly. No, 12.—The Female of the Black Hair-streak But- 
No. 5.—The Chrysalis of the Brown Hair-streak terfly. 
Butterfly. No. 13.—The Under side of the Black Hair-streak 
No. 6.—The Dark Hair-streak Butterfly (Thecla Butterfly, 
Pruni). No. 14.—The Caterpillar of the Black Hair-streak 
No. 7.—The Female of the Dark Hair-streak But- Butterfly. 
terily. . ; No, 15.—The Chrysalis of the Black Hair-streak 
No. 8.—The Wpder side of the Dark Hair-streak Butterfly. 
Butterfly. 
Tue fourth family of the Rhopalocera, or Diurnal Lepidoptera, is that of the Lycenide, 
containing three genera and twenty-one species, being above a fourth of the total number of 
British Butterflies. In this family the perfect insects of both sexes have six perfect legs fitted 
for walking. The larvie are short and onisciform. The Chrysalis is fastened by the tail, and 
also secured by a thread round the middle. The insects are generally much smaller than in the 
preceding families. 
The genus Thecla. The insects comprised in this genus present very marked characteristics, 
and group very homogeneously together. The hind wings have nearly always a narrow tail, 
The upper surface of the wings is generally of deep brown, with or without a patch or patches 
of orange ; the under side is often opaque gray, varied with delicate light streaks, from which 
they are called the hair-streaks, or with orange borders dotted with black. The Caterpillars 
and. Chrysalides of all the species accord with the characters assigned to the family. 
Thecla Betule (the Brown Hair-Streak, Nos. 1 to 5) is the largest of the genus. The male 
(No. 1) is smaller than the female, and the uniform deep brown of the upper surface of the 
Wings is only varied by a somewhat paler mark adjoining the short transverse black line in the 
centre of the anterior wings ; while the female (No. 2), which is much larger, is distinguished 
by a broad orange patch in the same position as the small pale mark in the male. The under- 
side (No. 3) is the same in both sexes. The Caterpillar (No. 4) feeds upon the foliage of the 
Birch and Blackthorn, &c., towards the end of June and beginning of July ; the perfect insect 
appearing in August. It frequents hedgerows, particularly in the southern counties. It is 
however a local, though far from a rare species. It has been recently taken at Blandford, 
Epping, Brighton, Lyndhurst, Peterborough, Teignmouth, Worcester, and other places. 
Thecla Pruni (the Dark Hair-Streak, Nos. 6 to 10) is smaller than the preceding, and the 
male is distinguished by an orange border on the hind wings. The female (No. 1) has an 
additional orange band near the edge of the front wings. The under side (No. 7) has the 
orange border with dots, above alluded to, and a narrow band or rather STREAK of white. The 
