JUAN VINAS— ABOVE THE LAGUNA 1 85 



Ascalaphid related to the ant-lions but differing from them 

 in having antennse as long as or longer than the body, and 

 knobbed at the tip. This individual presented a most 

 stretched-out appearance, for it had arranged itself with 

 antennse, body, wings, and hind legs held parallel to the 

 vine to which it clung, the wings being folded over the body 

 in roof-wise fashion. 



The current of the Naranjo was swift but there were 

 quieter pools in it here and there, owing to the numerous 

 stones in its bed forming partial dams. At one of these 

 pools, about 3 P. M. on August, 2 P. saw a male dragonfly 

 {Brechmorhoga pertinax eurysema) poising with rapidly 

 fluttering wings over a certain limited area. By gradually 

 lowering the net to within a few inches of the insect and 

 then bringing it down into the water as fast as I could, I 

 captured the specimen. No other dragonfly was nearby. 

 About 3,30 in precisely the same spot, another male of the 

 same subspecies was poising in the same place and was caught 

 in the same manner on the same square foot of water. About 

 4 o'clock a third male of the same subspecies was behaving 

 similarly in the same spot, but this one I failed to take; it 

 was alarmed by the attempt, flew away and I saw it no more. 

 What was there in this spot which had such an attraction 

 for this subspecies that three individuals took up their sta- 

 tion there — not on some stick or stone but hovering in the 

 air? 



We found three species of Brechmorhoga at Juan Vifias 

 and its vicinity, all of which possess eyes which in life are a 

 beautiful metallic bluish-green or greenish-blue. This color 

 is found In the eyes of many swift-flying dragonflles but Is 

 not correlated, as far as I could see, with the habit of life 

 as regards quantity of external light. B. pertinax eurysema 

 on the upper Naranjo was in deep shade, B. vivax on the 

 lower Naranjo near Its junction with the Reventazon In less 



