572 



Thorax pale blue and black, lackinjj the black stripes on the meta- 

 pleural sutures, and the femoral l)lack stripes almost wanting or re- 

 duced to short subapical lines. 



Abdomen with the pale and black markings similar to those of 

 the male; anal a])pendages of the usual type, the ovipositor with pro- 

 styles extending caudad to the apex of the anal appendages. 



Measurements 



Length, S 24 mm. 



Lonfjth. 9 29 mm. 



Length of abdomen, S 1!) mm. 



Length of al)domen, 9 18-22 mm. 



Length of hind wing.s, S 12 mm. 



Length of hind wing.s. 9 13-16 mm. 



"Width of hind wing.s. s 2f) mm. 



"Width of hind wings, 9 2.5-3.5 mm. 



A common species in soutliern and central Illinois, occurring in 

 the same localities where 'rcrtiailis is aliundant. The adults appear 

 usually somewhat later than Trrticcilis, and the earliest reared si)eci- 

 mens in my collection bear the date June I2, 191 5. 



Specimens have been seen from Havana, Peoria, and Urbana. 



ISCHNURA VERTICAUS (Say) 



A'yvil^li. — Color, pale green, buflf, or dark brown. 



Head broader than long, subelliptical, the caudo-lateral angles 

 with strong setae; .antennae with the first two segments and the prox- 

 imal third of tlu-ee dark, the remainder pale; first two segments sub- 

 equal, the third as long as the first two together; labium, when folded, 

 extending slightly caudad of the procoxae, with four or five mental 

 setae rmd six lateral setae, the lateral marginal setae of the median 

 lobe six or seven in number. 



Thorax nearly ecjual in diameter throughout; front femora with 

 a strong row of setae on the cei)halic surface and all the femora with 

 preapical rings of l)rown ; tibiae with several rows of apical setae, 

 two of which extend f.ar proximad ; wing-cases extending cautlad to 

 the fourth al)dominal segment. 



Alxlomen cylindrical and witii fecl)le lateral keels on segments 

 T-8, the margins .and ventral surfaces being thickly studded with short 

 setae; cuticle of the abdomen witli sm;dl dark spots from which minute 

 setae usually .arise, one to each spot; gills (Figs. 62. 65) with long 



