Of those diamonds of the night, the fire-flies and fire-beetles, there are numerous species. One of the most abundant--and of much larger dimensions than the rest of the elaters or beetles--pyrophorus noctilucus, called by the natives cocuja, displays both red and green light. On the upper surface of the thorax there are two oval tubercles, hard and transparent, like bull's-eye lights let into a ship's deck. These are windows out of which shine a vivid green luminousness, which appears to fill the interior of the chest. Then on the under surface of the body, at the base of the abdomen, there is a transverse orifice in the shelly skin, covered with a delicate membrane, which glows with a strong ruddy light; visible, however, only when the wing-cases are expanded. It is about an inch and a half long, of a brown colour, and has a strong spine situated beneath the thorax, which fits at pleasure into a small cavity on the upper part of the abdomen. By means of this machine it can, when placed on its back, spring up a couple of inches, and regain its feet. When preparing to do this it moves its head and thorax backwards, so that the pectoral spine is drawn out and rests on the edge of the sheath. The same backward movement being continued, the spine, by the full action of the muscles, is bent like a spring, and the insect at this moment rests on the extremity of its head and wing cases. The effort being suddenly relaxed, the head and thorax fly up, and in consequence the base of the wing-cases strike the supporting surface with such force that the insect by the reaction is jerked upward, while the projecting points of the thorax and the sheath of the spine serve to steady the whole body. So brilliant is the light of these creatures, that even one moved over the print of a book wall enable a person to read by it, while eight or ten placed in a clear glass bottle serve the purpose of a lamp. The Brazilian ladies ornament their dresses with these fire-beetles, by securing them so as not to injure the creatures; while they frequently wear several in the braids of their dark hair, which, when they walk abroad in the evening, has a curious and beautiful effect. [Gosse and Darwin.] Prescott relates that when the Spaniards first invaded America, on seeing the air filled with cocujas during the darkness of night, their excited imaginations converted them into an army with matchlocks, and they waited, expecting to be attacked by an overwhelming force. A similar story is told of the British, when first landing in the West Indies, being induced to hastily re-embark on seeing at night innumerable lights moving about, which they supposed were Spaniards approaching to defend the shore. SUSPENDED COCOONS.