116 EXPLANATION OF TERMS 



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 Hemerobndcc, 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 com- 

 posed 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 Cole- 



optera. 



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 Lcpidoptera, 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-se: 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. 



