The producers of these displays are the lightning-bugs,--beetles belonging to the family _Lampyridæ_ (Plate X., Fig. 7). They are mainly of small size and soft texture; the _larvæ_ being flat and dark colored, and often presenting the appearance of a bit of velvet. They are carniverous in their habits, and can be found under stones and the bark of trees. The velvet-hued _larvæ_ of one species is often seen on the surface of the snow, giving rise to stories of worm showers. The family is divided, generally, into three sub-divisions; and one, the _Lampyrinæ_, is noted for the phosphorescence of many of the species. Numerous species are known throughout the world and in this country, differing much in size; those in Kentucky and other Southern States being somewhat larger than their Northern cousins. In the South and the West-India Islands they are seen to best advantage. In these isles of summer, especially Jamaica, Gosse studied their habits, and observed their nocturnal glories; and to him I am indebted for the following notes relating to the West-India species. He says at all times their sparks, of various degrees of intensity, according to the size of the species, are to be seen, fitfully gleaming by scores about the margins of woods, and in open and cultivated places. He observed about fourteen species, all luminous. _Photuris versicolor_, a large species with drab-colored _elytra_, he found abroad soon after his arrival in December. One flying around the house in the evening, he was struck with its swift and headlong flight and nearly permanent luminosity, which was much more brilliant than that of any species he had at that time seen. The large _Pygolampis_, which he called afterwards _P. xanthophotis_, he did not observe until May, when one flew into his house at Bluefields one evening; and a few nights later he found them in great numbers on the very sea-beach at Sabito. It was conspicuous for the intensity of its light, much exceeding that of _Photuris versicolor_. Sometimes it is only the last segment but two that shows luminosity; but, when excited, the whole hinder part of the abdomen is lighted up with a dazzling glare. In June, in the woods of St. Elizabeth’s, Gosse had special opportunities for observing the _Lampyridæ_; particularly along the road leading up the mountain from Shrewsbury to Content, where it is cut through the forest, which overhangs it on each side, making it sombre even by day, and casting an impenetrable gloom over the scene by night. The darkness here, however, and especially at one point,--a little dell, which is most obscure,--is studded thick with fire-flies of various species, among which the two large ones above named are conspicuous. _Pygolampis xanthophotis_ he observed only in flight. Its light is of a rich orange color when seen abroad, but when viewed in the light of a candle appears yellow. It is not so deeply tinted as the abdominal light of _Pyrophorus noctilucus_, and is intermittent.