Aggregated: crowded together as closely as possible. Agnathous: without jaws; specifically applied to those Neuropteroid series in which the mouth structures are obsolescent. Aileron: the scale covering the base of primaries in some insects; see tegulae in Diptera = alula and squama, q.v. Air-sacs or vesicles: pouch-like expansions of tracheal tubes in heavy insects, capable of inflation and supposed to lessen specific gravity. Air-tube: a respiratory siphon. Ala -ae: a wing or wings. Alar appendage: see alulet. Alar frenum: a small ligament crossing the supra-alar groove toward the root of the wing: Hymenoptera. Alary: relating to the wings: applied also to the wing muscles of heart. Alate -us: winged; with lobes similar to wings in appearance though not necessarily in function. Albi, albus: white. Albicans: formed or made of white. Albidus: white with dusky tinge. Albinic: of the character of an albino. Albinism: that condition in which there is an absence of color or a whitening in a form usually colored. Albino: a colorless individual of a species that is normally colored. Albumen: the white of egg or the substances in the tissues which have the same characteristics. Albumin: the characteristic substance forming the white of egg. Albuminoid: like or of the character of albumen. Alimentary canal: the digestive tract as a whole; begins at the mouth and extends through the body to the anus. Alitrunk: that part of the thorax to which the wings are attached: in many Hymenoptera, includes the 1st abdominal segment. Alizarine: a transparent, orange red [alizar crimson]. Alleghanian faunal area: is that part of the transition zone comprising the greater part of New England, s. e. Ontario, New York, Pennsylvania, Michigan, Wisconsin, Minnesota, eastern N. Dakota, n. e. S. Dakota, and the Alleghanies from Pennsylvania to Georgia. Alligate -us: fastened or suspended by a thread; like the chrysalis of Papilio, etc. Alliogenesis: when the development includes an alternation of generations (q.v.), as in Cynipids. Alluring glands: glandular structures diffusing an odor supposed to be attractive to the opposite sex. Allux: next to the last joint of tarsus; in Rhynchophora. Alpine zone: = arctic zone, q.v. Alternation of generations: where a species that occurs in both sexes periodically produces only parthenogenetic females; the latter, in turn, producing the sexed form; occurs in Cynipidae and some Homoptera: see heterogeny. Altus: above: applied to a part raised above the usual level. Alulae: Diptera; a pair of membranous scales above the halteres, behind the root of the wing, one above or before the other; the anterior attached to the wing and moving with it, the posterior fastened to the thorax and stationary; see calyptra; squama; squamula; lobulus; axillary lobe; aileron; scale; tegulae: Coleoptera; a membranous appendage of the elytra which prevents dislocation.