Triacanthagvxa and Gynacantiia 



39 



brown, a trace of yellow at the extreme upper edge ; four spots on the 

 side and a latero-ventral stripe black ; sclerites between wings bright blue 

 (or those between front wings green). 



Abdomen reddish brown, i paler with an apical narrow transverse blue 

 bar, bordered very narrowly behind with black; 2 with a similar wider blue 

 bar (PD) and narrow green MDs, black bordered behind, reaching or not 

 to the auricles which are brown, edged with black; 3 with AL small, blue; 

 3-8 with AID and PD present and small, green in color, smaller and paler 

 progressively posteriorly, PD on 7 and MD and PD on 8 yellowish, 9 with 

 PD only ; 3-8 and 10 each with extreme apex black ringed ; 3-7 each nar- 

 rowly black edged on the lower lateral margin, PL, more or less distinctly 

 present. 



Female similar, only slightly duller, thorax above lighter, and AL, MD 

 and PD on 3-7 light dull yellow (probably green in some cases). 



In flight and environment this species so far as I have observed resembles 

 G. nervosa though it is possibly more wary and slightly more erratic. ?■ 

 Georgetown I took a single female flying alone at twilight in the Botanical 

 Gardens. At Bolivar it was flying at twilight with other species. At Palma 

 Sola it flew along the railroad tracks in the evening with G. nervosa. 

 Between the northeastern part of the town of Bejuma and the river, so 

 called, lying to the north are a number of artificial depressions, some with 

 shallow pools of water, formed by excavations for clay. There is no adja- 

 cent native forest, but there are scattered low bushes, and, at short distances, 

 some trees along the river and in nearby coffee plantings. The mud about 

 the pools is irregularly roughened by the sharp hoofs of visiting burros, and 

 in their deep tracks we found the females of mexicana ovipositing. Yellow 

 breasted flycatchers, resembling kiskeedees, at dusk from nearby bushes 

 watched the pools for the dragonflies. No attempts were made by the birds 

 to capture the swift flying males but when a female alighted and descended 

 into one of the burro tracks there was usually an observant bird ready to 

 take advantage of her helpless position. Alighting over the depression the 

 bird seized the dragonfly at her work several inches below the surface. No 

 other species of Gynacantha was found at these clay diggings. Along the 

 grade for the railroad Y at Fundacion are a number of shallow, muddy pools 

 formed by excavations for the railroad grade. Here we found mexicana 

 flying at dusk, coming from over the adjacent pastures to patrol the pools, 

 returning again to the wider range of pastures. 



Material examined: Colombia, Bolivar, near Santa Marta (December 

 21 and 24, 1916, 3 females, E. B. W.), Fundacion, Dept. Magdalena (Janu- 

 ary 9 and 10, 1917, 2 males, i female, E. B. W."), Ecuador, San Rafael (F. 

 Campos R., i male, i female, A. N. S.), Babahoyo (F. Campos R., 

 I male, A. N. S.) ; Venezuela, Palma Sola, Dept. Falcon (March 7-10, 1920, 

 5 males, 3 females. E. B. W.), Bejuma, Dept. Carabobo (February 12-23, 

 1920, 7 males, 5 females, E. B. W.), El Guayabo, Dept. Zulia (April 20, 

 1920, I female. E. B. W.) ; British Guiana, Georgetown (February 18, 1912, 

 I female, E. B. W.) ; Bra-il, Para (C. F. Baker, i male, E. B. W.). 



