36 University of California Publications. [Entomology 



root set in a cavity of the body wall, to which the wing is 

 attached, and upon which it rotates during flexion. Eight 

 veins may be recognized in the basal attachment of the wing. 

 The first vein is the strongest one found in the wing. Its basal 

 end is abrupt and does not articulate with the wing-roots, but 

 continues toward the anterior root as a soft tubular sheath of 

 the distal portion of the extensor muscle. This vein is closely 

 appressed to the second, but is, through much of its course, 

 always distinct from it. 



The second vein is about equally prominent on both sides of 

 the wing, except near the base, where it ipS entirely ventral. 

 Just before the liase is reached the vein appears to split into 

 two branches, the anterior of which may be considered as a 

 cross vein binding this vein to the first. The posterior branch 

 is doubtless the lower portion of the posterior wing-root. 



The third vein resembles closely the fourth vein in dragon- 

 flies in its shape and distal connections. Proximally it lies 

 almost directh' over the base of the second vein and is contin- 

 uous with the posterior wing-root above; in the same manner 

 the second vein connects beneath. These two veins form the 

 hinge for the flexion of the wing. 



The fourth vein is very closely approximated to the fifth, 

 except at the two extremities. Toward the basal end it 

 becomes abruptly feeble, but rapidly widens again, and from 

 some points of view appears double. The extreme 1mse is 

 formed b}- a vertical process that articulates above with the 

 tip of the posterior wing-root. 



The fifth vein is quite prominent, being dorsad of the fourth, 

 and in connection with the sixth vein expands at the base 

 into a broad, flat, elevated plate, that lies partly over the 

 posterior wing-root, especially when the wing is flexed. 



The sixth vein, besides uniting with the fifth in the forma- 

 tion of the plate just described, comes into close relation with 

 the body by fitting into a groove along the side of the scutum 

 and into the catcli formed at the end of the postscutellum; it 

 also is closely associated with the hind wing, forming the 

 catch that holds the latter expanded. A portion of the poste- 

 rior edge of this vein is black and fuses with the seventh. 



The seventh vein lies close along the sixth, somewhat ven- 

 trad to it, and contributes to the formation of the catch for 

 the hind wing. The whole vein really belongs to the posterior 



