Radiate veins: the longitudinal veins spreading fan-like in the anal field of secondaries: = anal veins; q.v.
Radiated: marked with lines proceeding from a common centre.
Radicle or Radicula: that joint of the antenna that is articulated to the head.
Radio-medial cross vein: connects the radial and medial systems and usually closes the radial cell (Comst.).
Radius: (Comst.); the third of the longitudinal veins starting from base and dividing into not more than five branches before reaching the margin: the branches are numbered 1, 2, 3, 4, and 5, respectively, beginning at the costal margin and extending outward and downward.
Radix: base of wings, and their point of insertion; see pteropega.
Ramification: the branching out in every direction.
Ramify: to branch out in every direction.
Rammel-kammer: = copulation chamber; q.v.
Ramose -ous: branched, or having long branches.
Rapacious: predatory; capturing and eating prey.
Raptoria: applied to that series of Orthoptera, in which the anterior legs are fitted for grasping; Mantidae { Scanner's comment: No longer Orthoptera, but Mantodea, a suborder of the Dictyoptera.}
Rasorial: formed for scratching; applied to leg structures.
Receptaculum seminis: a sac or pouch-like appendage at the junction of the oviducts with the vagina; it is filled during copulation and the eggs are fertilized from it as they are extruded.
Reclinate: directed backward; e.g. the bristles in Diptera.
Reclivate: curved into a convex, then into a concave line.
Recondite: the sting when concealed in the abdomen.
Rectal cauda: the terminal, tubular process or tail terminating the abdomen of some male Hemiptera.
Rectal glands: appendages to or thickenings of the rectum secreting a lubricating material.
Rectal tracheal gills: lamelliform structures in the rectum of the nymphs of some Odonata, supplied with trachea and tracheoles and serving as respiratory organs.
Rectangular: in the form of a right or rectangle.
Rectangulate: forming or meeting in a right angle.
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.