104 Annals Entomological Society of America [Vol. IV, 



Between the hours of two and four of June 15 about twenty 

 emergings were witnessed from one view-point in a narrow swift 

 portion of Coy Glen Brook. The nymphs popped from the 

 surface of the water and flew unsteadily upward in the sunlight 

 for about 20 or 30 feet when they veered into the tree tops or 

 settled on the side of the gorge. 



Iron fragilis sp. no v. 



Measurements. 

 Length of body Length of setae Length of Wing 

 Male imago 7 m. m. 21 m. m. 7 m. m. 



Male subimago 6.5 m. m. 14 m. m. 



Female imago 7 m. m. 15 m. m. 



Female subimago 6.05 m. m. 14 m. m. 



Male imago. (Plate X, figs. 2, 3 and 4). (In alcohol). Body 

 extremely delicate and fragile. General hue dull yellowish white, 

 appearing hyaline in segments 2-7 of the abdomen. Eyes, conspicuous, 

 grayish. Head, parchment color with the eyes gray, darker below; 

 antennae, light brown except for white basal segment; ocelli, ringed with 

 conspicuous, broad band of dark brown. Thorax, yellowish shading 

 brownish above, pale below. Pronotum deeply notched behind. The 

 lateral lobes of the pronotum and the median portion of the meso- 

 thorax shaded brown. A sub-triangular area of brown on either side 

 of the median posterior elevations of mesothorax and metathorax. 

 Legs, dull yellowish, the femora with a conspicuous dark brown spot 

 at the middle. Tarsi with joinings and claws brown. Forelegs (PI. 

 X, fig. 3) longer than the body, its tarsal claws identical with those of 

 the other two. Wings, (PL X, fig. 2) hyaline, sub-hyaline near the tip 

 in costal and sub-costal regions. Abdomen. Tergites 1-9 with their 

 posterior borders delicately shaded by transverse bands of brown growing 

 more distinct posteriorly. Sternites, pale. Forceps pale, broad at the 

 base and conspicuous (PL X, fig. 4). Setae 2, pale slightly brownish 

 at the base. 



Male sub-imago. The sub-imago differs most markedly from the 

 imago in the following respects. The forelegs and setae are shorter, 

 the forceps less conspicuous, and the wings are of the usual grayish 

 sub-hyaline appearance. Head with occiput brownish. Bands of 

 ocelli less prominent than in the imago. Thorax, brown, prominent 

 ridges of mesothorax and metathorax shaded with brown, but without 

 definite sub-trangular markings. Pleurae and sternum with ridges 

 shaded brown. Coxae suffused with brown. Abdomen with tergites 

 1-10 suffused with brown, the transverse band of brown more distinct 

 than in the imago. An irregularly shaped patch of white in the center 

 of each segment near the pleura. The posterior lateral angles of the 

 tergites whitish. 



Female imago. Body heavier than that of the male, all over dull 

 yellowish color; legs of nearly equal length; setae 2. Head with eyes 



