565 



Chromagrion CONDITUM (Hagen) 



Nymph. — Color, dark brown. 



Head half as long as wide, the caudo-lateral angles projecting 

 strongly; labium, when folded, extending caudad to the procoxae; 

 mental setae three and sometimes a small fourth; lateral setae five; 

 proximal segment of the palpus with a distinct hook at the apex of 

 the mesal process and the median lobe with a slight notch at the apex. 



Thorax : femora with two dark rings and a double row of setae 

 on the ventral surfaces; tibiae with a single basal ring of brown; 

 wing-cases reaching caudad to the fifth abdominal segment. 



Abdomen slender; lateral keels feebly developed and without 

 setae; gills long and slender, widening gradually to near the apices, 

 then suddenly contracted, the margins setose, the setae far apart and 

 increasing in size distad ; color of gills uniform dark brown, except 

 that the tips are light; indistinct blotches of darker pigment occur 

 around the margins of the gills; smaller tracheae transparent and 

 indistinct. 



Measurements 



Length 17 mm. 



Length of abdomen 10 mm. 



Length of gills 6 mm. 



Width of gills 1 mm. 



Length of median lobe 2 mm. 



Width of median lobe 6-1.6 mm. 



Described from fragments of several exuvia obtained from Dr. 

 J. G. Needham, and the description completed from data given by 

 Needham in his description of the species ('03: 247). 



Adult; Male. — Color, blue, black, and yellowish orange. 



Head black and dark brown and buff ; mouth-parts yellowish, the 

 labium pale, the median lobe subtriangular in outline, the cleft broad 

 and deep ; labial palpi pale, the distal segment also pale ; antennae nearly 

 black, the first segment nearly as long as the second ; postclypeus black, 

 the anteclypeus, labrum, mandibles, their trochantins, genae, and the, 

 front above the clypeus to the level of the antennal fossae, greenish 

 blue ; remainder of the vertex, occiput, and postgenae black. 



Thorax black and blue, the pronotum largely black, the cephalic 

 lobe, a small spot on the lateral margins of the median lobes, and the 

 lateral margins of the caudal lobe, pale; proepimera and pro- 

 episterna bluish green, the dorsal borders black; mesostigmal 

 plates long and triangular, the lateral angles pale ; mesepisterna with a 



