Rectigrade: larvae which, having sixteen feet, walk with a rectilinear body. Rectilinear: in the form of a straight line. Rectum: a chamber, variable in size and form, just within the anus, in which the excretions are formed or molded for expulsion from the body:= cloaca. Rectus: right or straight. Recumbent: lying down; reclining. Recurrent: running backward: applied to nerves it = stomatogastric. Recurrent nervure: in Hymenoptera (Nort.), is the medial cross vein (Comst.), from the point of branching to the junction. Recurrent vein: in Hemerobiidae, the first branch of the subcosta when it recurves toward the base of the wing. Recurved: bowed backward. Reductus: a zig-zag marking or corrugation. Reflected or Reflexed: angularly bent backward. Refracted: bent back as if broken. Region: a space or area adjoining a specified point: a part of the body composed of a number of segments, as the head, the thorax, or the abdomen. Rejuvenescence: a renewal of youth; bringing back to a condition of youth. Remote: further removed than distant. Reniform: kidney-shaped: applied to a macula approximating that shape, found at the end of median cell in many moths. Repand: wavy; with alternate segments of circles and intervening angles. Replicate: wings folded back upon the base; like the secondaries in Coleoptera. Replicatile: capable of being folded back. Repugnatorial: serving to repel: so offensive as to drive away: applied to glands that secrete an offensive material. Reservoir: a case or cavity for the storage of any fluid or secretion. Resilient: elastic; having the property of springing back. Respiration: breathing or taking breath: union of oxygen with tissues and liberation of carbon dioxide from same. Restricted: held back: confined to a limited area. Resupinate: upside down; horizontally reversed. Rete: the fatty mass of insects: also applied generally to any structureless membrane or layer. Reticulate: like net-work. Reticulum: a net-work; as of a cell. Retina: that portion of the eye upon which the image is formed. Retinaculum: in Lepidoptera, the loop into which the frenulum of the male is fitted; = hamus, q.v.: in Hymenoptera, horny, movable scales serving to move the sting or to prevent its being darted out too far: in Coleoptera, the middle, tooth-like process of the larval mandible. Retinal pigment: the pigment layer of the compound eye just above the basilar or fenestrate membrane. Retinophora: = retinula; q.v. Retinula -ae: the retina of a single ocellus: the nerve fibres or cells between pigment cells and retina of the compound eye. Retracted: drawn back; opposed to prominent. Retractile: capable of being drawn in or retracted. Retractor: used in drawing in or back; as a muscle. Retroarcuate: curved backwards. Retrocession: the going or moving backward. Retrose: (sinuate), pointing backwards; (serrate) inversely serrated.