1918.] NATURAL SCIENCES OF PHILADELPHIA. 151 



small: mediastine vein straight in the greater portion of its length, 

 bearing eight costal veins, remainder of costal veins seven in nmnber, 

 all non-clavate; discoidal vein almost straight; medio-discoidal area 

 broad, divided by sixteen regularly placed, transverse nervures into 

 subquadrate areolets; median vein arcuato-sinuate ; medio-ulnar 

 area narrower than the medio-discoidal area, similarly divided, but 

 with veins fewer and less distinct; ulnar vein with one complete 

 ramus, which is bifurcate close to its origin, and three incomplete 

 rami; axillary vein biramose. Dorsal abdominal segments of the 

 type characteristic of Ischnoptera:^ supra-anal plate transverse, 

 lateral margins regularly converging caudad, the distal margin trun- 

 cate, its vicinity with long, sparse hairs ; when viewed from the caudal 

 aspect there is seen to be dextrad, briefly mesad of the cercus, a thick, 

 curved projection, which points mesad, and is distinctly tapering 

 distad, the whole structure well hidden under the margin; cerci 

 relative heavy, rather short, subequal in width for the greater por- 

 tion of the length, rather abruptly tapering distad, depressed dorsad, 

 rounded ventrad, with a close, adpressed coat of short hairs and scat- 

 tered, erect, long hairs: subgenital plate moderately asymmetrical; 

 sinistral margin with a broad, deep emargination ventrad of the cer- 

 cus, relatively short, median section concave-truncate, dextrad of 

 which is a short, deeply arcuate emargination, with a moderate pro- 

 jection separating it from the oblique subtruncate and then (proxi- 

 mad) arcuate remainder of the same margin; both principal emargi- 

 nations with their margins somewhat thickened and the plate there 

 appreciably convex in section, between them the plate is concave dis- 

 tad; styles unequal, the sinistral one twice as large as the dextral, 

 situated at the lateral angles of the median subtruncate section, in- 

 crassate, tapering, with the apex bispinose, the distal spine larger, 

 decurved, the other spine situated slightly proximad of the apex, 

 straighter; when viewed from the caudal aspect the plate is seen to 

 have an incrassate arm extending mesad from the projection of the 

 dextral margin, this arm reaching to the median line of the body, 

 supplied at the apex with long hairs and on the cephalic face with a 

 number of spines : genital hook sinistral in position, the distal portion 

 sinuate, V-shaped, narrowed at the bend of the structure, slightly 

 thickened and blunt distad. Cephalic femora with ventro-cephalic 

 margin with four large, proximo-mesal spines, these followed distad 

 by a regular series of very short, fine spines; distal spines three in 



9 See Hebard, Trans. Amer. Entom. Soc, XLII, pp. .339 to 340, pis. XVI and 

 XVII, (1916). 



