This paper is an account of the life histories and habits of several Staphylinidæ. The adults of this large family are too well known to require any particular description. The active, elongate beetles, with their short elytra that leave exposed most of the abdominal segments, are found in a variety of places. Many are carrion feeders and are popularly associated with the Silphidæ by reason of their similar habits. They are also found in dung, in ants' nests, under the bark of trees, on the moist banks of streams and ponds, and in decaying animal or vegetable matter of all sorts.