The _Lycoenidoe_[1], a particularly attractive group, abound near the enclosures of cultivated grounds, and amongst the low shrubs edging the patenas, flitting from flower to flower, inspecting each in turn, and as if attracted by their beauty, in the full blaze of sun-light; and shunning exposure less sedulously than the other diurnals. Some of the more robust kinds[2] are magnificent in the bright light, from the splendour of their metallic blues and glowing purples, but they yield in elegance of form and variety to their tinier and more delicately-coloured congeners. [Footnote 1: _Lycana polyommatus, &c._] [Footnote 2: _Amblypodia pseudocentaurus, &c._] Short as is the eastern twilight, it has its own peculiar forms, and the naturalist marks with interest the small, but strong, _Hesperiidoe_,[1] hurrying, by abrupt and jerking flights, to the scented blossoms of the champac or the sweet night-blowing moon-flower; and, when darkness gathers around, we can hear, though hardly distinguish amid the gloom, the humming of the powerful wings of innumerable hawk moths, which hover with their long proboscides inserted into the starry petals of the periwinkle. [Footnote 1: _Pamphila hesperia, &c._] Conspicuous amidst these nocturnal moths is the richly-coloured _Acherontia Satanas_, one of the Singhalese representatives of our Death's head moth, which utters a sharp and stridulous cry when seized. This sound has been variously conjectured to be produced by the friction of its thorax against the abdomen, and Reaumur believed it to be caused by rubbing the palpi against the tongue. I have never been able to observe either motion, and Mr. E. L. Layard is of opinion that the sound is emitted from two apertures concealed by tufts of wiry bristles thrown out from each side of the inferior portion of the thorax.[1] [Footnote 1: There is another variety of the same moth in Ceylon which closely resembles it in its markings, but I have never detected in it the utterance of this curious cry. It is smaller than the _A. Satanas_, and, like it, often enters dwellings at night, attracted by the lights; but I have not found its larvæ, although that of the other species is common on several widely different plants.] _Moths._--Among the strictly nocturnal _Lepidoptera_ are some gigantic species. Of these the cinnamon-eating _Atlas_, often attains the dimensions of nearly a foot in the stretch of its superior wings. It is very common in the gardens about Colombo, and its size, and the transparent talc-like spots in its wings cannot fail to strike even the most careless saunterer. But little inferior to it in size is the famed Tusseh silk moth[1], which feeds on the country almond (_Terminalia catappa_) and the palma Christi or Castor-oil plant; it is easily distinguishable from the Atlas, which has a triangular wing, whilst its [wing] is falcated, and the transparent spots are covered with a curious thread-like division drawn across them.