88 
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 (Sparganium eurycarpum) 
beside the stream. A number of exuvize 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 (772, p. 5, Pl. IL, 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 (795, p. 209) observed the imagos 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. 111) 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 apex; 
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. 
