Vol. XXVli] ENTOMOLOGICAL NEWS. 351 



Tumatumari, British Guiana, February 7, 10 and 12, 

 1912, 15 males, 3 collected by A. F. Porter. Along Tiger 

 Creek, especially on the right bank near Washerwoman Falls, 

 are more or less extensive pools left by gold diggers. These 

 pools are grown up with vegetation, and are very suggestive 

 of old brick yard pools or deserted gravel pits in Indiana. 

 However, some of these placer mining pools are very small, 

 being only a few feet long and 2 or 3 feet wide. On the right 

 bank of the creek below Washerwoman Falls the pools are 

 more extensive and are immediately adjacent. Here we 

 found both Perithemis lois and thais. Apicale was found 

 about these placer pools and nowhere else. It is the hand- 

 somest Acanthagrion I know, and is an unusually conspicuous 

 and alert agrionine. 



Acanthagrion ascendens Calvert (Plate XVII. fig. 13). 



Abdomen: $, 27-29; average, 28; 9, 26.5; hind wing $, 17-19; 

 average, 18; 9, 18.5 mm. 



$ . Genae, labrum and rhinarium green or olive, labrum marked 

 as described for kenncdii. Nastis black, yellow and green in varying 

 proportions ; the green is confined to the lateral borders, the black may 

 form a broad crescent inside this, the horns resting at either side on 

 the posterior edge of the nasus, the curve reaching the anterior border 

 of the nasus in the median line, from which median part a longitudinal 

 median black line projects backward, dividing the enclosed yellow into 

 two spots of varying size ; the horns of the crescent, in its minimum 

 development, may not reach the posterior border of the nasus, and the 

 longitudinal median black line may be incomplete in which case the 

 enclosed yellow is constricted, not divided, in the median line; in the 

 maximum development of black the green lateral borders remain, but 

 the yellow is reduced to a small spot on either side just anterior to the 

 posterior border, or the black may occupy even this area ; in extreme 

 cases of minimum black the black crescent consists of only three 

 spots, one median and one on either side, the median spot with or 

 without a posteriorly directed prolongation. Frons in front with a yel- 

 lowish or greenish bar on either side as described for kenncdii; the 

 obliquity of these bars results in a low broad triangle of black on the 

 lower edge of tbe frons, the apex of the triangle produced dorsally 

 in the median line in a bar of black of varying width to the dorsal 

 black of the head ; usually the pale quadrangular bars are confined to 

 the frons in front but in tlu-ir maximum development (minimum 

 black) they are extended over the frons above and, in a 1 in tad mass of 



