S488 BRITISH BUTTERFLIES. 



gregariously at night has often been remarked upon, and, at such 

 times, the $ s often appear to be fairly conspicuous, resting high up 

 on the plants, where they can be readily seen. Thus it is reported as 

 being observed on Gaddon Down, near Cullompton, swarming on the 

 flowering-heads of Avena flavescens, where they had gone to rest 

 (Angus); swarms also amongst the long grass, on which it passes the 

 night, in the Isle of Portland (Richardson), and Rollason records the 

 species as swarming in a sheltered valley on the north coast of 

 Cornwall, on June 14th, 1901, whilst at sundown they were observed 

 asleep on the grass stems. It is also noted as sitting at night on the top- 

 most twigs of the ling on the heaths at Wokingham (Horton), and at rest 

 in numbers on the heather at Oxshott (James) . Arkle records that, in the 

 Delamere Forest district, it was in hundreds on June 30th, 1900, all^ s, 

 flying in company with Polyommatus icarus, the 2 s had become equally 

 abundant by July 19th, when both sexes were observed about 5 p.m., 

 asleep on the heather- tops, in every case resting head downwards ; at 

 the same place, on July 14th, 1906, they were again seen, in fine 

 condition, resting at sunset, in scores, head downwards, on an unusually 

 prominent furze-bush, whilst, on June 11th, 1893, the insect, which was 

 swarming on the heaths and sandhills at Abersoch, was, by 7 p.m., 

 conspicuously seated on the marram grass, some two dozen being 

 counted in a square yard. Prideaux observed it at rest in dull weather, 

 in very great numbers, on bracken fronds, in its South Devon resorts. 

 Habitats. — A species that exists in suitable places from the marshes 

 of the Mediterranean littoral in the neighbourhood of Hyeres, the arid 

 plains of Spain, the shores of the Baltic Sea, and the moorlands of 

 Finmark, to the altitude of the Riffel Alp, and from Ireland 

 through every country of Europe and Central Asia to Japan, 

 is not likely to be found wanting in great variety in its habitats, 

 if sufficient enquiry be made concerning them. In Britain, the 

 species may be said to prefer three very distinct and different kinds 

 of places for its home. In the south of England it usually occurs 

 either on the rough, uncultivated patches that are so frequent 

 on the great ranges of chalkhills that dominate large portions 

 of our southern counties, or on the great tracts of heather-covered 

 gravel and sand that are so locally abundant, and reach their maximum 

 probably in the New Forest district ; it also haunts similar localities 

 in other parts of England, Ireland and Scotland, but, in the northern 

 counties of England, it is particularly attached to the moorland bogs 

 that are so frequent among the heathery-covered slopes of our northern 

 mountains. Occasionally, as noted by Lewin, it occurs in low rushy 

 meadows, whilst, on the continent, the corner of a quiet flower-covered 

 pasture, or of a little disturbed lucerne patch is often its chosen haunt, 

 and it sometimes swarms on the lower pastures of many of the alpine 

 valleys of central Europe. It is also found in Britain on wild 

 commons, especially if broom or heather be abundant, but it is a local 

 species, and is often strangely and inexplicably circumscribed within a 

 small spot, when acres of similar-looking ground is apparently within 

 easy access. Above Hailing, a typical chalk-down locality consists of 

 a rough slope covered with bramble, scabious, ragwort, sainfoin, and 

 numberless other chalk-loving plants in tangled confusion, and it 

 occurs thus in many places on the chalk-hills on both sides of theMed- 

 way ; it also occurs on the long ridges above the precipitous parts of Box 



