D = the Abdomen has numerous ringed sections; in the Sub-order, Cyclorrhapha in eight segments, but commonly divided into four or five conspicuous segments and three or four more smaller, less visible, and much modified in the sexual terminal segments.
D, I, the first abdominal segment is the Basal Segment.
D, II, the last of those more visible is the Anal Segment or Anus.
D, III, the abdominal termination, see plate VI, fig. 17.
D, IV, the chief segments consist each of an Upper Plate joined to an Under Plate by Membranous Sides, often concealed.
D, V, Abdominal Bristles, see plate VI, fig. 41.
E = Bristles, Hairs, etc.; fine short furry hairs are called Pubescence; "Hairs" are longer and stronger; Bristles are still stronger; but a very thick bristle is called a Spine, if on the costa, and a Spur, if on the leg; the larger bristles on B or on D are called Macrochætæ.
F = Stripes and Bands; a long marking, when parallel (or nearly so) to the major axis of the body, leg, or wing, is called a Stripe; when lying at right angles (or nearly so) it is called a Band. For "frontal stripe" see A, III (1).
O = Cells of the wing [see the following Table]; the rib-like nervures are termed Veins; these divide the area of the wing into more or less twelve compartments called Cells or Areolets.
V = Longitudinal Veins [see the following Table]; two groupings within the margin can be recognised; the principal veins of the Fore Region are numbered, 1, 2, and 3, whilst those of the Hind Region are numbered, 4, 5, 6 and 7 respectively; some have branches, a, b, c, etc., when sections (separately referred to) may have index numerals attached.