296 ENTOMOLOGICAI, NEWS. [July, '15 



exuviae, but none of them had an imago with it. They were 

 chiefly on the rock face of the waterfall but in spots more or 

 less protected from the falling water. Smaller larvae than 

 those indicated by the exuviae were crawling over the rocks. 



This waterfall was nearly vertical in its descent from the 

 top of the canyon of the Rio Reventazon but, at about one 

 hundred feet above the railroad track (which occupied a nar- 

 row ledge cut out of the cliff face), the water usually dis- 

 appeared beneath a mass of boulders and flowed underground 

 through loose soil to reappear on the slope far below the 

 track. Up over these boulders we climbed to the foot of the 

 actual fall with its vertical rock face. The amount of water 

 over and among the boulders varied with the rains. On April 

 26 we ascended with more difficulty than usual, owing to the 

 greatly increased flow of water which covered many of the 

 usual footholds. Mrs. Calvert, who was in advance, found a 

 large larva on the wet slippery face of the fall itself in such 

 a position that a small projection above it gave it shelter from 

 the direct spray. This larva we saw transform. She noted 

 at the time: "Unlike other dragonflies we have watched 

 transform, the wings while they hang limp and wet, in fact 

 until they are full size and dry, are green. The body of the 

 dragonfly is brown and green and as the creature hangs on the 

 rocks, the body and wings giving the little trembling jerks 

 that usually accompany the growing or 'filling out' of a trans- 

 forming dragonfly, the likeness to a green leaf on a stem 

 trembling in the breeze is very marked. There is a great 

 deal of a small-leaved Commelina on the face of the fall as 

 well as some delicate grasses, both of a bright pea-green, and 

 we ourselves frequently confused the dragonfly we wanted 

 to watch with one or other of these if we happened to move 

 our eyes from it. It certainly seems to be a good case of pro- 

 tective coloring." Her record of the progress of transforma- 

 tion follows: 



10.30 A. M. Head and thorax free dorsally. 



10.35. Antennae and head entirely free, wings beginning to be with- 

 drawn. 

 10.37. Front wings free. 



