Basal line: in many Lepidoptera; a transverse line extending half way across the primaries very close to base. Basal lobe: of culicid genitalia, see claspette. Basal post-costal vein: in Agrioninae, one of the cubito-anal cross-veins. Basal segment of clasp: see side piece. Basal space: that area on the primaries of certain Lepidoptera, between the base and t. a. line (q.v.). Basal streak: in Noctuid moths, extends from base, through the submedian interspace to the t. a. line. Basal transverse carina: on the metanotum of Hymenoptera, crosses before middle and separates the anterior from the median areas. Base: that part of any appendage that is nearest the body: on the thorax that portion nearest the abdomen; on the abdomen that portion nearest the thorax. Basement membrane: that thin layer of tissue upon which the epithelium rests. Basilar: of or pertaining to the base. Basilar cross-vein: Odonata; crosses the basilar space. Basilar membrane: a thin membrane separating the cones and rods from the optic tract. Basilar space: Odonata; that area at base of wings, between media and cubitus. Basi-proboscis: basal third of the flexed proboscis of muscid flies. Batesian mimicry: see mimicry. Bathmis: see pterostigma. Bave: the fluid silk as it is spun by caterpillars. Beak: any notable prolongation of the front of the head: the snout in Rhynchophora: specifically, the jointed structure covering the lancets in the hemipterous mouth. Bearded: fringed with hair: see barbated. Belly: venter; under side of abdomen. Belonoid: needle-like. Bi: prefix, means two. Bi-alar: two-winged; applied to Diptera. Biarcuate: twice curved. Biareolate: with two cells or areoles: see bilocular. Bicaudate: having two tails or anal processes. Bicolored: with two colors that contrast to some extent. Bicornute: with two horns or cephalic processes. Bicuspidate: ending in two points or cusps. Bidactylate: with two fingers or finger-like processes. Bidentate: two-toothed. Biemarginate: twice emarginate; with two excisions. Bifarious: pointing in opposite directions. Bifasciate: with two bands or fascia. Bifid: divided into two parts; split; applied in Coleoptera to tarsal claws which are divided so that the claws lie side by side: see biparted. Biflabellate: antennae with fan-like process on two sides. Bifurcate: divided, not over half its length, into two dull points; forked. Bifurcation: a forking or division into two: the point at which a forking occurs. Biguttate: with two drop-like spots. Bijugum: in two pairs. Bilamellar: divided into two lamina or plates. Bilateral -eriter: with two equal or symmetrical sides. Biliary vessels: see malpighian tubules. Bilineate -us: with two lines. Bilobate -ed: divided into two lobes. Binocular: having two cells or compartments: see biareolate. Bimaculate: with two spots or maculae. Binate: in pairs: consisting of a single pair. Binotate: with two rounded spots. Binus: paired: doubled.