556 



as early as the tenth of May and the greatest number of adults appear 

 on the wing about June i. The latest emergence which is recorded 

 is one on June 25, 191 5. This gives a period of emergence of at least 

 a month and a half. 



Specimens have been seen from Havana, Lake Villa, Muncie, 

 Peoria, and Urbana. 



Enaixagma traviatum Selys 



Nymph. — Color, very dark brown. 



Head about one-third as long as broad, dark in color ; caudo- 

 lateral margins projecting caudad, studded with short setae; antennae 

 very slender, the first two segments with setae and of much greater 

 diameter than the remaining ones, the third segment longest, the 

 second decidedly shorter than the first ; labium extending slightly cau- 

 dad of the first pair of coxae ; mental setae two, with sometimes a rudi- 

 mentary third, lateral setae four; marginal setae of the median lobe 

 six or seven. 



Thorax : lateral portions of the prothorax and the metapleura 

 darker than the dorsum of the thorax; legs slender, the coxae dark 

 brown, femora almost wholly devoid of setae, but with very distinct 

 preapical brown rings ; tibiae with setae which are rather closely set, 

 especially towards the apices ; tarsi pale. 



Abdomen brown, darker immediately above and below the lateral 

 keels ; cuticle with a few minute setae, but lacking minute black spots 

 entirely; lateral keels feebly developed and without heavy setae, there 

 being instead a few setae near the apices of the keels; gills (Fig. 55) 

 rather narrowly lanceolate, the median gill entirely without heavy 

 setae on the dorsal margin ; lateral gills with the ventral marginal row 

 of setae extending one-half or less of the length of the gills; basal 

 two-fifths or one-half of the gills uniform dark brown, the pigmented 

 area followed by a broad white or clear band extending from margin 

 to margin and including the axes ; beyond the clear portions there are 

 frequently one or two brown transverse stripes, the apex of the gills 

 being without pigment ; ovipositor extending caudad to the apex of 

 the tenth sternum, the ventral margins of the lateral valves with one 

 or two heavy setae and a number of hairs. 



Measurements 



Length 11 mm. 



Length of abdomen 8 mm. 



Length of gills 6 mm. 



Width of gills 1 mm. 



