22 University of Michigan 



largely dull orange yellow in ictericiim, is black or dark brown 

 above, paler below in melanurmn, with a narrow obscure pale 

 basal ring which widens at the lower lateral margin. Super- 

 ior appendages brown, paler basally ; rudimentary inferiors 

 yellow. 



Legs yellow, femora each with two large brown or black 

 areas, dividing the femur into five subequal areas; a trace of 

 darker at base and apex. 



Wings clear or with a very slight brownish tinge ; stigma 

 brown or black, covering from scarcely two to two and one- 

 half cells; two postquadrangular cells in all wings but one 

 hind wing where there are two minus ; postnodals of front 

 wing are 15 to 19, of hind wing 14 to 16; the arculus is distal 

 to the cubito-anal cross-vein about .3 mm. or slightly less in 

 both front and hind wings ; the anal vein separates from the 

 posterior border from less than .4 to .5 mm. distad to the cub- 

 ito-anal cross-vein. 



Female. — Not known. 



Material Studied: Wismar and Rockstone, British Guiana, 

 January 30 to February i, 1912, four males, collection E. B. 

 W. Type male, Rockstone, February i, 1912. 



The darker abdomen and the slenderer appendages will 

 separate this species from its close ally, ictericnm. 



5. Heteragrion triangular e Selys 



Figures 17, 18, 112, 137, 138 



The type is a female from southern Brazil in the ]\Iuseum 

 of Vienna (i). In 1886 de Selys described an incomplete 

 male and female from Rio Janeiro in McLachlan's collection 

 and referred them to triangulare, with the remark that it was 

 uncertain that the specimens were the same as the unique 



