132 Annals of the Carnegie Museum. 



the same, April 7, 1899, 2 cT 1 9, April 8, 1 9, and April 20, 1899, 

 1 (5\ Academy of Natural Sciences of Philadelphia. 



45 #. Argia gerhardi nigrior subsp. nov. 



d\ Differing from the typical gerhardi in that on the lowest fourth 

 of the mesipimeron is a black spot as wide as the pale antehumeral 

 stripe and continued in subequal width upon the mesinfraepisternum ; 

 nearly all the remainder of the mesipimeron is pale brown with less 

 bronzy-green reflection than in gerhardi type ; the black stripe on 

 each side of abdominal segment 2 reaches to the hind end of the seg- 

 ment by a narrow prolongation of its lateral edge. These differences 

 appear to be indicated in teneral examples also. 



Stigma of the front wings surmounting more than one (60 percent. ), 

 one (33.3 per cent.) or less than one (6.7 per cent. ) cell ; of the hind 

 wings surmounting more than one (97 per cent.) or less than one 

 (3.3 per cent.) cell. 



Antenodal cells on the front wings 4 (93 per cent.), 3-1- (3.3 per 

 cent.) or 3 (3.3 per cent.) ; on the hind wings 3 (97 per cent.) or 

 3 -f- (3.3 per cent.). Percentages based on 15 cT- 



9 . The single female which can be referred here differs from the 

 same sex of typical gerhardi by having the ninth abdominal segment 

 entirely black ; it does not possess the black mesepimeral spot of the 

 male. 



Dimensions : Abdomen c? 26-29, ? 2 7 > hind wing c? 19—21, 9 

 21.5 mm. 



Habitat : Bolivia, near Coroico, Yungas, by W. J. Gerhard, April 

 11, 1899, 6 c?, May 9; 1 ?; road to Coroico, April 19, 3 c? ; twelve 

 miles northeast of Coroico, by the same, May 20, 1899, 9 d\ May 

 24, 1 d\ Academy of Natural Sciences of Philadelphia. 



That nigrior is a geographical, not a seasonal, form of gerhardi is 

 evidenced by the facts that typical gerhardi and nigrior were taken at 

 nearly the same time, and that the peculiar markings of nigrior are 

 indicated in teneral (immature) individuals. 



46. Argia kokama sp. nov. 



(Plate IV, figs. 71, 715-.) 

 cT. Black of the frons reaching down between the bases of the 

 antennae as a moderately wide band to the riasus. Rear of the head 

 black, a very narrow pale stripe bordering the eye-margins inferiorly. 



