Atrium: a chamber just within the spiracle and before the occluding structure to the trachea. Atrocoeruleus: very deep, blackish, sky-blue. Atrophied: wasted away; unfit for use. Atropurpureus: dark purplish, nearly black [an admixture of mauve and black]. Atrous: jet black. Atrovelutinus: velvety black. Atrovirens: dark green, approaching blackish [prussian green]. Attenuated: drawn out; slender; tapering. Attingent: touching. Atus: suffix; denotes possession of a quality or structure. Atypic -ical: off type; not of the usual form. Auchenorhynchus: with the beak issuing from the inferior portion of head, as in Homoptera. Auditory: relating to the sense of hearing. Auditory organs: Orthoptera; specialized structures covered by a tense membrane, on the anterior tibia or base of abdomen; any structure that functions as an ear. Aurantiacus: orange colored; a mixture of yellow and red [chrome orange]. Aurate: with ears or ear-like expansions: also = auratus. Auratus: golden yellow [pale cadmium yellow]. Aurelia: = chrysalis or pupa; specifically of butterflies. Aurelian: a lepidopterist. Aureolate: with a diffused colored ring. Aureole: a ring of color which is usually diffuse outwardly. Aureous -eus: gold-colored. Aurichalceous: brassy yellow. Auricle -cula: an appendage resembling a little ear; in Odonata the tumescent area at the sides of the second abdominal segment: in Andrenidae, a short membranous process placed laterally on the ligula. Auricular: applied to the space or cavity surrounding the dorsal vessel. Auriculate: with an ear-like appendage or, in antennae, with the basal joint distended into a concave, plate-like ear which envelops the rest of the structures. Auriculo-ventricular: the outer valves of the heart between the auricular space and the chamber. Auriculo-ventricular openings: are the lateral openings into the heart by means of which the blood is admitted into it. Auritus: with two ear-like spots or appendages. Auroral spot: applied to the bright orange colored spot at the apical area of Anthocharis. Auroreous -eus: red, like the aurora borealis [crimson lake]. Austral: is that faunal region which covers the whole of the United States and Mexico except the boreal mountains and tropical lowlands: divided into transition, upper, lower and gulf strip: see boreal and tropical. Austroriparian faunal area: that part of lower austral zone covering the greater part of the South Atlantic and Gulf States. Begins near mouth of Chesapeake Bay, covers half or more of Virginia, North and South Carolina, Georgia, Florida, Alabama, all of Mississippi and Louisiana, east Texas, nearly all of Indian Territory, more than half of Arkansas and parts of Oklahoma, s. e. Kansas, so. Missouri, so. Illinois, s. w. corner of Indiana and bottom lands of Kentucky and Tennessee. Autotype: any specimen identified by the describer as an illustration of his species and compared with the type or co-type.