AGRION. 83 



Hob. Philadelphia; Berkeley Springs, Ya. (Osten Sacken); 

 Pecos River, Western Texas (Capt. Pope). 



The colors in the living insect were communicated to me by 

 Baron Osten Sacken. 



17. A. prognatum! 



Agrion prognatum Hag*en ! 



Green-brassy, varied with green ; head above green-brassy, the 

 mouth and a point upon each side of the occiput bright green ; 

 posterior margin of the prothorax very short, with a small tuber- 

 cle upon the middle ; dorsum of the thorax green-brassy, each side 

 with a bright green stripe ; sides green, with two short green-brassy 

 stripes at the wings ; feet pale, knees exteriorly lineated with black ; 

 abdomen slender, green-brassy, the sides, and a basal lunule upon 

 segments 3 6, green ; segment 9 entirely, and 10 with the sides 

 bluish-green ; the tenth segment has an elevated process upon the 

 middle of the posterior margin, which is long, cylindrical, black, 

 the apex yellow ; superior appendages bifid, the exterior branch 

 long, narrow, laminated, incurved ; the inferior branch hardly 

 shorter, yellow, curved downwards ; the inferior appendages yel- 

 low, unguiculated ; wings hyaline, pterostigma large, rhomboidal, 

 snow-white, interiorly brownish-black ; eight postcubital cross- 

 nervules (< ). 



Length 35 millim. Alar expanse 36 millim. 



Hob. Berkeley Springs, Ya. (Osten Sacken). 



The colors of the living insect were made known to me by Baron 

 Osten Sacken. 



18. A. pollntiira ! 

 Agrion pollutum Hagen ! 



Brassy-fuscous ; head brassy-fuscous, in front and a cuneiform, 

 occipital spot each side orange ; hind margin of the prothorax 

 rounded ; dorsum of the thorax brassy-fuscous, each side with a 

 broad orange stripe ; sides yellowish, with a black line inferiorly; 

 feet yellowish, knees sublineated with fuscous ; abdomen long, 

 slender, brassy-fuscous ; sides yellow, lateral margin yellow ; seg- 

 ments 2 6 with a basal yellow annulus ; 9 entirely and 10 sides 

 blue (<), or the apex of 9 and the whole of 10 blue (9); appen- 

 dages, superior ones long, with the apex broader, dolabriform ; 



