OF NORTH AMERICA. 35 



ZYGJENIDJE. 



ZYG^ffiNINJl. 



Genus GNOPHSILA. walker. 



" Head moderate, rather small, as are the eyes, which are not very 

 full; clypeus globose, swollen, projecting in front; two occelli, before 

 and between which the epicranium is roundedly elevated, rising to a 

 ridge behind; maxillae moderately developed, when unrolled, not so 

 long as the thorax. Palpi slender, extending beyond the head, held 

 nearly horizontally and on a plane with the 

 body, third article somewhat depressed, not 

 pointed. Antennas of the male somewhat 

 shorter than those of the female, finely bipec- 

 tinate, the pectinations tapering just before 

 the tip, and are more separated and fewer, 

 compared with the male antennas in Ctenu- 

 cha. In the female the pectinations are shorter and stouter, bearing 

 terminal setae. Legs unarmed and finely scaled. Abdomen some- 

 what exceeding posterior wings. Quite similar in external conforma- 

 tion in both sexes. 



"Anterior wings more than twice as long as broad; costal margin 

 straight, slightly depressed before costal angle; external margin round- 

 ed, not very oblique; internal margin straight. Discal space open; 

 sub-costal nervure arcuated before the apex, crowding the nervules to- 

 gether; first and second sub-costal nervules approximate at base ; third 

 being short, throwing off a branchlet just before the margin; second 

 thrown off before the fifth, on the opposite side of the vein, while in 

 Clenucha it arises much beyond; apical interspace widening towards 

 costa; fifth sub-costal nervule thrown off directly from the nervure, not 

 removed as in Clenucha, towards the middle of the discal area. First 

 and second median nervules united at base; second greatly nearer the 

 first than the third, which latter is bent downwards; fourth much re- 

 moved from third. Sub-median nervure perfectly straight, and parallel 

 with internal margin. 



" Posterior wings nine veined; discal space partially closed, the vein 

 becomins: towards the centre a mere thickening of the membrane. 



