The _butterfly_ is out in May and June, and is sometimes seen much later. It is generally met with on limestone or chalky soils; and, from a long list of localities I have looked over, it seems to be distributed over England, Scotland, Wales, and Ireland. * * * * * {153} THE MAZARINE BLUE. (_Polyommatus Acis._) (Plate XIII. fig. 5, Male; 5 _a_, Female.) _Colouring_:--Upper side, male, _deep purple, or mazarine blue_, with a _border of black_ (fig. 5); female, _dark brown_ (fig. 5 _a_). Under sides of both sexes similar, _pale greyish drab_, tinged at the base with greenish blue, numerous _black spots in white rings_. No red spots. Though this elegant butterfly was frequently met with some years ago, it has lately become one of our rarest species, and I can give no locality where it can be now found. It has been _reported_ as taken lately at Ventnor, Isle of Wight, and somewhere in South Wales, also in other places, but only singly. Collectors, on visiting any new district, should net all the Blues they are not _quite_ sure are common ones, and this may perchance turn up among them sometimes. The _caterpillar_ is said to feed on the flower heads of common Thrift (_Armeria vulgaris_). The _butterfly_ may be _looked for_ in July. * * * * * {154} THE LARGE BLUE. (_Polyommatus Arion._) (Plate XIV. fig. 1.) This is the _largest_ of all our "Blues," and, next to the last, the rarest, though still taken in some numbers every year. _Colouring_:--Upper side, _dark blue_, granulated with black scales that give it a dull aspect, having a black border, and a series of _large black spots across the front wing_. Under side, greyish drab, suffused with greenish blue near the body; towards centre, many black spots in indistinct light-coloured rings, and a double border of the same. _No red spots._ The _caterpillar_ is _unknown_. The _butterfly_ appears in July, frequenting rough, flowery pasture-grounds, but is exceedingly local. A famous place for it is Barnwell Wold, about a mile and a half from the village of Barnwell, near Oundle, Northamptonshire, where the insect was discovered by the Rev. W. Bree many years ago; but it is less abundant there than formerly, from the repeated attacks of collectors, who catch all they can find. Other localities, mentioned in various works, are--Brington, Huntingdonshire; Shortwood, and some other spots, near Cheltenham; Charmouth, Dorsetshire; Dover; Downs {155} near Glastonbury, Somerset; Downs near Marlborough, Wiltshire; Broomham, Bedfordshire; near Bedford; near Winchester. * * * * * THE CHALK-HILL BLUE. (_Polyommatus Corydon._) (Plate XIV. fig. 2, Male; 2 _a_, Female.) _Colouring_:--Upper side, _male, pale silvery greenish blue_, with very silky gloss, and shading off into a _broad black border_.