BUTTEBFISH. 732 BUTTERFLIES. BUTTERFISH (for origin of name see be- low). Any of several fishes. The best known is a bleniiy ' (.Uiirfrnouics ifuiDicllus) . about 12 inches lonj?, olivo-brown in color, with obscure bars and spots, called also 'gunneir and 'rock- eel.' It is abundant in the North Atlantic. ( See GuNNEix. ) In New York and .Massachusetts the name applies to one of the harvest-fishes of the Stroniateidje, allied to the mackerels. It is oval, about 10 inches long, bluish above and silvery below, and known to science as Jllioinbiis iriacandius. It owes its name to the bulter-likc feeling of its surface, and it is highly esteemed as food. Lafayette, harest-fish ( referring to the time of its ajipearance), and dollar-fish (due to its roundish form and silvery hue) are other local names. Similar species belong to the north- west coast. A third 'butterfish' is a small yel- low or reddish serranid {Epinephelus punctatus) of Florida and the West Indies — one of the groupers (q.v.) ; and a fourth is a popular long- tin {Chilndaclijhis nigricans). See Longfin; Habve.st-Fisii. BUTTERFLIES AND MOTHS ( the name is ])rolialily due to llic ]iii]iular In-lii-f that it steals butter and milk; or it may refer to the color of the excrement; cf. JI. Dutch botcrscliijlc, Scheie}. Insects of the order Lepidoptera which are not separable by any distinct line of structural char- acters. (See Lepidoptera.) They agree in essentials and their popular separation is a prac- tical rather than a natural one. Perhaps the nearest we may come to a definite distinction is to call hultci'flies all those Lepidoptera whose pairs of wings are never fastened together in flight; and call moths all those whose wings are so united. ■"The popular division of Lepidoptera into 'butterllics' (Rhopalocera ) and 'moths' (Hetero- cera) is quite unscientific, the butterllics being more nearly ndatcd to the higher moths than these to the lower mollis. It has been proposed to separate the three lowest families • which have ... a jugum on each fore wing, as Jugatie, from all other Lepidoptera — Frenatic; also to divide the families with incomplete pupa> (Ineompletae) from those with obtect pupae (Obtecta") ; also to separate the lowest family on account of the structure of the first maxilla; as a suborder (Laciniata) distinct from all other families (Ilaustellata) . On the whole, it is bet- ter not to adopt any division of the Lepidoptera between the order and the family." (G. H. Car- penter, Insects, New York, 1899.) Butterllics, as a rule, go abroad in the daytime, seeking no concealment, and are brightly colored, while moths more usually fiy in the twilight or at night, and are sut)ducd in hue. Uulterllies are distinguislied by the terminal knob (or occa- sionally hook) of the antenmie, whence the com- mon group-name Ithopaloccra, while the antenniE of moths (Heterocera) are usually otherwise in form, often filiform or feathery. Bulterfiies have the habit of holding the wings in a vertical posi- tion over the back wlien at rest, while moths usually keep them flat. Of the Lepido])tera represented in North Amer- ica, the following families may be called butter- flies: Hesperiida', Lyc;enid«, Lcmoniidsp. Nym- phalids, and Papilionidie; and all the rest moths, among which the Pterophorid;r. Tineidse, Tortricid.T, Pyralida-, Geonietrid*. Nootuidie, Bombycida", Zygtenidse, .iEgeriidoe, and Sjiliingidte are most important. Other families of both sorts belong only to South America or the Old World. StkuctI'RE, The head in this group is distinct from the thorax, clothed with hairs, and bears large, compound eyes, and moths have also sim- ple eyes (ocelli). The antenna' are always pres- ent, and important not only as feelers, but as organs of hearing and smell (see Insect), the latter service being probably a verj' important one in this group. These antennic take various shapes. Among butterflies they are thickened at the end, sometimes into a rounded club, but more often into a spindle-shape terminating in 0- bent point. Of the moths "some have thread- like antenniE tapering to a fine point ; others have feather-shaped antennse; others still have antenna? which are prismatic in form, and pro- vided with a little hook or spur, at the end: and there are many modifications and variations of these forms." The sha])e, or at least the size, usually varies between the se.xes, being larger in the male than in the female — a fact connected with his duty to search for her, and especially observable in moths. The same may be said of the eyes, which, in the nocturnal species, cover the whole side of the head and have an enormous number of facets — 27,000, it is said, in some hawk-moths. The mouth in the Lepidoptera is modified into a sucking-organ, enabling tliis insect to feed on the nectar of flowers and the sap of trees and plants. The mandibles are rudimentary or ab- sent, and the maxillfe. by a very extraordinary development and modification, are formed into a sucking-tube, called the proboscis, wliidi. when not in use, is coiled up between two forward- Itrojeeting organs, the labial palpi. It is "com- posed of three distinct hollow tubes, soldered to each other along their inner margins," and "has much the appearance of a double-barreled gun, with a third tube lying below." Nutrition is imbibed through the lower or central tube, by a regular pumping, produced by the alternate muscular pinching and loosening of a bulb-like arrangement in the head; and the other tubes admit air. In some of the spliinx-moths the ])roboscis may be ten inches long, and in others its tip is armed with spines which serve to break or cut the surface of fruits, the juice of which is sucked up. Wini/s. — The thorax bears the legs and wings. The former are weak and are merely used as organs of support when the insect is at rest, and the front pair of legs may be short or rudimen- tary, as is the case in Vanessa. The four mem- branous wings are usually large in comparison with the size of the body; expanse of wing and strength of flight, however, are not exactly cor- related, for some of the hawk-moths with pro- [lortionately small wings are the most enduring flyers, yet the large-winged forms probalily fly with less exertion. In actual size Icpidopteraiis vary from almost microscopic species, hiding in the moss, to tropical monarclis 12 inches in ex- panse. These transparent membranes are sup- I)orted by a framework radiating from the thoracic joints, which consist of double horny tubes (veins or 'nerves' and nervules) one within the other, the inner being filled with air and the outer with nutritive fluids. "These 'nerves,' as custom will jiersist in terming them, in the but- terflies, take a bow-like or ellipsoidal sweep from the base of the wing, forming what is the 'discoi- dal cell,' whence there branch off to the edges a
