28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5 1 



1)2) Fourth longitudinal VEIN incomplete, straight, not forked, reaching 

 neither the wing margin nor the third vein, normal, ending at or before wing- 

 tip, angular or rounded at bend, bowed or not beyond bend, bend approximated 

 to or removed from hind margin of wing; last section forming petiole of 

 apical cell when latter is petiolate, or third vein in such case forming petiole; 

 or forked and main vein represented beyond apical crossvein by only a -hurt 

 stump, or by a mere wrinkle or fold in the wing-integument, or by a long 

 stump. 



2) Apical crossvkix (this term should be employed only when the fourth 

 vein is furcate, or shows indication of previous furcation in a stump, told or 

 wrinkle) bent in, straight, oblique, long, short, absent. 



1) Fifth LONGITUDINAL VEIN bent up to fourth vein, net forked; or furcate. 

 giving off posterior crossvein: represented beyond latter by a short stump, or 

 a long one, or only by a wrinkle, or partly by stump and wrinkle, or continu- 

 ous to wingborder. 



1)2) Posterior crossvein (term not to be employed in the few cases where 

 fifth vein shows no sign of furcation) oblique, in line with apical crossvein or 

 with last section of fourth vein, or still more oblique than latter, or normal ; 

 nearer to bend of fourth vein (or to origin of apical crossvein) than to small 

 crossvein, or nearer to latter, or about in middle between the two; trisinuate, 

 bisinuate, singly curved, straight. 



2) Small crossvein* on. before, "i" behind middle of discal cell; short, long, 

 straight, oblique, direction. 



1)2) Apical cell (first posterior of descriptions) ending near wingtip 

 far before; open, closed in margin, or long or short petiolate, or extremely 

 short petiolate: wide, narrow, short, elongate, tapering equilaterally at apex. 



2) Tegul^E large, small, relative size of two scales; deeply smoky or in- 

 fuscate, or while, or yellow; bare, pubescent, or hairy. 



(Abdomen) 



1)2) Abdomen (shape of whole") linear, cylindrical in one or both sexes, 

 widened on some portion, conical or oval in both sexes, swollen, convex dor- 

 sally, concave ventrally, flattened in one or both sexes, or laterally compressed. 



1) Abdominal SEGMENTS apparently four, or how many visible from above; 

 bow many actually present, which ones shortened, and relative development 

 of their respective dorsal and ventral plates. [See notes on Gymnosoma. 

 Trichopoda, Rhacho'epalpus, etc., under head of Descriptions. In many cases, 

 at least, there are more segments in the Muscoidean abdomen than have here- 

 tofore been recognized, an undeveloped basal segment being quite bidden from 

 view, and only visible with difficulty on the sides below. Its dorsal and ventral 

 plates are easily seen on detaching the abdomen. In order to avoid confusion, 

 the old terms "first," "second,"' "third," and "fourth"' segments are retained as 

 referring to those apparent from above in the undetached abdomen.] 



2) Abdominal macroch.et.e present or absent, bristle-like, true, very strong, 

 thorn-like, discal and marginal, or only marginal ; discal present on second and 

 third segments (counting apparent segments from above), or only on third 

 and fourth, or only on fourth ; marginal present on all, or absent on first, or 

 absent on both first and second segments. 



1) Ventral membrane < membrane connecting the ventral and dorsal plates 

 of the abdominal segments) visible, concealed by the sides of the dorsal 

 sclerites or plates, or apparently absent. 



