CHAP. XVI.] 
THE BRITISH ISLES. 
327 
preservation of some of the numerous species which are or have 
been dependent on it. 
Mr. McLachlan has kindly furnished me with some valuable 
information on certain species of Trichoptera or Caddis flies 
which seem to be peculiar to our islands ; and this completes 
the list of orders which have been studied with sufficient care to 
afford materials for such a comparison. We will now give the 
list of peculiar British Insects, beginning with the Lepidoptera, 
and adding such notes as have been kindly supplied by the 
gentlemen already referred to. 
List of the Species or Varieties of Lepidoptera which , so far as at present 
lenoicn , are confined to the British Islands. (The figures slioiv the dates 
when the species was first described.) 
Diurni. 
1. Polyommatus dispar. u The large copper.” This fine insect, once 
common in the fens, but now extinct owing to extensive drainage, is 
generally admitted to be peculiar to our island, at all events as a variety 
or local form. Its continental ally differs constantly in being smaller 
and in having smaller spots ; but the difference, though constant, is so 
slight that it is now classed as a variety under the name of rutilus. 
Our insect may therefore be stated to be a well-marked local form of a 
continental species. 
2. Lycsena astrarclie, var. artaxerxes. This very distinct form is con- 
fined to Scotland and the north of England. The species of which 
it is considered a variety (more generally known to English entomo- 
logists as P. agestis ) is found in the southern half of England, and 
almost everywhere on the continent. 
Bombyces. 
3. Lithosia sericea. North of England (1861). 
4. Hepialus humuli, var. hethlandica. Shetland Islands (1865). A 
remarkable form, in which the male is usually yellow and buff instead 
of pure white, as in the common form, but exceedingly variable in 
tint and markings. 
5. Epichnopteryx reticella. Sheemess, Gravesend, and other localities 
along the Thames (1847). 
6. E. pulla, var. radiella. Near London, rare (1830?) ; the species in 
Central and Southern Europe. (Doubtfully peculiar in Mr. Stainton’s 
opinion.) 
Nocttle. 
7. Acronycta myricae. Scotland only (1852). A distinct species. 
8. Agrotis subrose a. Cambridgeshire and Huntingdonshire fens, perhaps 
extinct (1835). The var. subccendea is found in Finland and Livonia. 
