peating them at uncertain intervals; and in old houses, where these insects are numerous, it may be heard, especially if the weather be

warm, almost every hour of the day. You

must not confound this insect, which is the

real Death-watch of the common people, with

a much smaller insect, of a very different genus, which makes a sound like the ticking of a watch, and continues it for a long time without intermission.

Fifth genus, luster.

The insects belonging to this genus, as well as their larva, are mostly found about dunghills. Their habits are either unknown, or not remarkable. They are small, of a coal black, and a flat shape.

Sixth genus, Gyrinus.

The Gyrinus natator is probably well known to you, under the name of the water-Flea, forming circles on the surface of the water, by its very brisk motions. Its curious structure, so admirably adapted to its manner of life, is deserving your attention. The antenne are short and stiff, appearing to consist of one undivided piece; but the microscope showss that they are composed of very numerous, close-set joints. The hinder legs are very broad, finely webbed with minute hairs, and most curiously formed for the purpose of fins

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