ing-cages in June failed to transform, one being still alive on 

 September 28. In 1897 two full-grown nymphs were taken 

 June 22 along shore in the quiet weedy waters of Quiver Lake, 

 not far from the mouth of Quiver Creek. The only imago seen, 

 emerged June 23 from a nymph which we found that day 

 crawling up some blades of bur-reed [Sparjiioiiiim t'to'ijcarpum) 

 beside the stream. A number of exuviae have been observed at 

 various times during June and July on Sagittaria stems, brush- 

 wood, and the bases of tree trunks along the margin of the 

 creek, from near its mouth to McHarry's Mill, a few miles above. 



Cabot (72, p. 5, PL XL, Fig. 1) described the nymph from 

 examples taken in Massachusetts July 4, one of them partly 

 transformed, and Hagen ('85, No. 26, p. 270) redescribed it. 



Kellicott ('95, p. 209) observed the images in Ohio Sep- 

 tember 4 flying about and ovipositing "in a manner similar to 

 that of the Libellulas^'' in a small brook that was rippling over 

 pebbles, and he later ('96, p. Ill) gives the time of flight as 

 August and September. Williamson found the adults trans- 

 forming abundantly in western Pennsylvania July 4, and also 

 records the species from Tennessee (August) and New York 

 (September). The imago was originally described from Rock 

 Island. Other Illinois localities for the imago are Bloomington 

 and the Mackinaw River at the " Dells." 



The nymph measures in length 40 mm.; abdomen, 29 mm.; 

 hind femur, 5 mm.; width of abdomen 7 mm., of head 5 mm. 



Body very elongate and posteriorly attenuate, sparsely 

 hairy on lateral margins and on appendages. Tibial hooks 

 minute. 



Labium elongate ; mentum widened toward the ax^ex ; 

 median lobe with a very straight front border ; lateral lobes 

 arcuate, with a long-pointed sharply incurved end hook, and on 

 the inner side one to three teeth, though sometimes only the 

 middle one is distinct. These teeth are widened distally, and 

 obliquely truncate so that they appear directed backward. 

 Movable hook long, strong, and more strongly curved toward 

 the tip. 



