452 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105 



interval. Since the theory seems plausible, and in order to create 

 less confusion with the identification of Nearctic Neuroptera, the 

 principal features of Martynov's and Carpenter's terminology are 

 used in this paper. 



The labeling of some of the veins in this paper is provisional, 

 but is done in order to facilitate the definition of a genus or species. 

 Variations and abnormalities in the wing venation are frequently • 

 seen in the following: gradates in the "doubling" of certain cross- 

 veins where a second is found adjacent to the normal one, the oc- 

 casional absence of a cross-vein usually present, or addition of one 

 not normally present; the relatively basal or distal position of a cross- •] 

 vein; the direction of the cross-vein; the forking of a longitudinal ( 

 vein far basad or distad of its usual point of forking; the addition! 

 of branches of longitudinal veins to the margin; and the difference of 

 venation seen in the two wings of the same specimen. Color and size 

 variations can also occur. The unstable nature of the veins should 

 be taken into consideration when venation is used for the determination 

 of a species. 



The vague definition ascribed to the term "gradate veins" hasi 

 also led to confusion. Gradate veins are supposed to run obliquely 

 across the wing, usually in the distal half, and more or less paralleli) 

 with the outer margin. Or, in the sense of Bradley (1939, p. 36), 

 gradate veins are a series of cross-veins alternating with parts of 

 longitudinal veins, forming a regular zigzag line across the wing 

 In this paper, those cross-veins considered gradates are those other 

 than the basal series (as 1st r, basal m between MA and MPl+2,J 

 1st m between MA and MPH-2 (M5 of Tillyard, 1919, p. 533),1 

 1st and 2d m-cu between MP and Cu, cubital, cubito-anal and anali 

 cross-veins) . Specifically, the shorter inner gradate series will include 

 2d r, basal s, 1st r-m, 2d m between MA and MPl +2, 1st m between 

 MPl+2 and MP3+4, and the usually longer outer gradate series,- 

 including 3d r, distal s, 2d r-m, 3d m between MA and MP14-2. 

 m between MPl+2 and MP3+4, and 3d m-cu, when present. 



A trichosor consists of a thickening of the membrane upon which 

 stand several macrotrichia, somewhat elongate in form along the 

 apical portion of the margin but becoming shorter and smaller towards 

 the bases of the inner and costal margins, as of Killington (1936(j 

 pp. 34-35), or the marginal "dots and dashes" of Comstock (1918' 

 p. 167). Thyridia — in the sense of a weakening of the vein becaustj 

 superposed by a concave fold or in the sense of small whitish or almos I 

 transparent spots, or the "bullae" of Comstock (1918, p. 81) — can b<| 

 seen in the forewing at the point where MP forks basally, on the cubij 

 to-anal and anal cross-veins in the forewing, on the medial cross-vein; 

 and on the radial, medial, and mediocubital cross-veins of the oute 



