Ephemeran

An ephemera. See EPHEMERIDE. Ephemeridæ, n. pl. (Zool.) The Day -fly, a family of insects, sub-order Neuroptera. They have received their name from the brief duration of their existence in the perfect state, in which, very unlike the dragonflies, they are believed to take no food, merely propagating their species, and dying. From the season of the year in which they begin to be seen, some of them are also called MAY-FLY. The larvæ and pupsæ are aquatic, and in these states the E. have a much longer life than in their perfect state, extending even to years. The larvæ and pupæ are sufficiently voracious. The abdomen of the larva is furnished on each side with a set of leaflets, which serve instead of gills for respiration, and are also used in locomotion, although there are six feet attached to the thoracic segments. The pupæ differ little from the larvæ, ex Fig. 948.-DAY-FLY. ( Ephemera.) cept in having rudimentary wings enclosed under scales. Both larvæ and pupe have the abdomen terminated by two or three jointed filaments, which the perfect insect also has, sometimes, very long. The body of the perfect Insect is soft and slender; the wings resemble in form those of dragon-flies, but are soft and filmy; in repose they are elevated vertically above the body; the second pair of wings are much smaller than the first, and in some species are altogether wanting; the organs of the mouth are so soft and small as not easily to be discerned, and to be apparently unfit for any kind of use. E. , in their larva and pupa states, live chiefly under stones in water, or in burrows which they make in the banks of streams. When ready for their final change, they creep out of the water to undergo it on some plant or other object by the water-side, generally towards sunset on some fine day of summer or autumn. After having attained their winged state, however, they cast off a complete slough or envelope, so perfect, that it exhibits even the limbs, abdominal filaments, and antennæ, and these "ghost-like exuviæ are sometimes so abundant in the neighborhood of streams, as to cover in "a pearly layer" the hat and basket of the angler. The multitudes of E. are often very great, filling the air as a cloud; nay, so abundant are they at times, that their bodies have been known to cover the ground in certain districts of France, and have been gathered from particular spots in cart-loads to be used as manure. Ephem'eris, n.; pl . EPHEMERIDES. [Gr. See EPHEMERA.] A journal or account of daily transactions; a diary. An astronomical almanac, or a table which exhibits the state or positions of the heavenly bodies at noon, for a number of succe ive days. - A collective name for reviews, magazines, and all kinds of periodical literature. Ephemerist, ( ef-em'e-rist,) n. One who studies the diurnal motions and positions of the planets; one who practises astrology. - A journalist; one who keeps an ephemeris.