A class of animals of very low organisation and generally of small size, having a jellylike body, from the surface of which delicate filaments can be given off and retracted for the prehension of external objects, and having a calcareous or sandy shell, usually divided into chambers and perforated with small apertures.

Containing fossils.

Having a faculty of digging. The Fossorial Hymenoptera are a group of Wasp-like Insects, which burrow in sandy soil to make nests for their young.

( pl. Frena ): A small band or fold of skin.

( sing. Fungus ): A class of cellular plants, of which Mushrooms, Toadstools, and Moulds, are familiar examples.

The forked bone formed by the union of the collarbones in many birds, such as the common Fowl.

An order of birds of which the common Fowl, Turkey, and Pheasant, are well-known examples.

The genus of birds which includes the common Fowl.

A swelling or knot from which nerves are given off as from a centre.

Fishes covered with peculiar enamelled bony scales. Most of them are extinct.

A minute vesicle in the eggs of animals, from which the development of the embryo proceeds.

A period of great cold and of enormous extension of ice upon the surface of the earth. It is believed that glacial periods have occurred repeatedly during the geological history of the earth, but the term is generally applied to the close of the Tertiary epoch, when nearly the whole of Europe was subjected to an arctic climate.