BRITISH BUTTERFLIES 
og 
ra 
The caterpillars of this genus are not found on herbaceous plants, but frequent trees and shrubs, over which 
the perfect insects fly. The species are very numerous, although we possess but very few ; and even amongst 
those some very peculiar distinctions occur. Thus, in Thecla Quercus (contrary to the general rules of insect 
colouring), the female puts on the “imperial purple : ” the fulvous patch in the fore wing of the female of Thecla 
Betule is found in the females of some exotic species, the males of which are adorned with the purple tint, 
whereas the males of Thecla Betulz are obscurely coloured. The males of Thecla Rubi, Spini and W-album are 
distinguished by having a small ovate glabrous patch at the extremity of the discoidal cell of the fore wings on 
the upper side*. Th. Rubi differs from all the rest in not having the hind wings tailed, and by the underside of 
the wings being neither marked with the slender pale hair-streak, nor by an ocellus at the anal angle. 
Dr. Horsfield, who has described twenty-six species of these insects, found in Java, has divided the genus into 
two subgenera, Thecla proper and Amblypodia. Unfortunately, however, he did not investigate the peculiarities 
of the veins of the wings of his subgenera and sections, a character which the reader need scarcely be reminded 
has been already shown, in the pages of this work, to be of primary importance in determining natural groups. 
Although previously so greatly neglected, this character supplies the means of dividing our English species into 
two primary groups}, which ought, perhaps, consistently to be considered as distinct subgenera, supported as they 
are by some other characters. It is, however, perhaps more advisable (until the exotic series of species is carefully 
investigated), to leave the genus entire, indicating the groups into which the British species are divisible. This 
plan is also adopted, because the investigation of the peculiarities in the veining of the wings is attended with 
great difficulty, the scales having to be carefully removed from the surface of the wings. It is certainly remark- 
able that we should find, in species so closely allied together as all the British Thecle are, such a variation in the 
veins ; more especially as we have seen that nearly all the Nymphalide, varying as they do, so greatly in their 
preparatory as well as perfect forms, exhibit an identity in the arrangement of these veins—but Nature, in every 
extensive group, shows us the impropriety of trusting to a single character, which, in some tribes, may be most 
important and constant, whereas, in others, it may become variable and of secondary importance. 
Retaining Thecla Betule as the true Fabrician type of the genus, I divide it in the following manner : 
I. Those in which the postcostal vein of the fore wings emits two branches before its union with the ordinary 
transverse vein, and a third branch beyond its union therewith; this third branch sending forth a superior 
branchlet. Males without a patch at the extremity of the discoidal cell of the fore wings ; antenna: with the club 
very gradually formed. 
Sp. 1. Thecla Betule. 2. 'Thecla Quercus. | 
IL. Postcostal vein of the fore wings emitting, in both sexes, three simple branches before and none after its 
union with the ordinary transverse vein. Males with a thickened patch at the extremity of the discoidal cell of 
the fore wings; antenne with the club more suddenly ‘formed. 
A, with the hind wings tailed. 3. Thecla Pruni. 4. Thecla W-Album. 5. Thecla Spini. 6. 
Theela Tiicis. 
B, with the hind wings not tailed. 7. Thecla Rubi. 

* This is produced by the dilatation of the base of the 2nd and 3rd branches of the postcostal vein. 
+ Hiibner unites all the Thecle into one family (Fam. C. Armati), of his Adolescentes, separating Rubi under the generic name of Lycus, and 
(Quereus under that of Bithys ; the remainder forming his Strymon. Ochsenheimer gives our Thecla as the third family of Lycena, separating, 
however, Rubi from the rest, and uniting it with the second family, containing the Coppers. 
