76 
The nymph measures in length 32 mm.; abdomen, 20 mm.; 
hind femur, 6 mm.; width of head 5.5 mm., of abdomen 8 mm. 
Body stout, only moderately depressed. Lateral margins 
of body and appendages hairy. Tibial hooks very prominent. 
Labium short and stout; mentum a little longer than broad 
and narrowed at basal third ; median lobe very faintly rounded; 
lateral lobes short, thick, and not strongly arcuate, ending in 
two teeth which are hardly distinguishable from the five to ten 
other teeth which extend in a diminishing series down the in- 
ner margin; movable hook short, stout, tapering, and regularly 
curved to its tip. 
Abdominal segments 3-8 about equal, 9 one half longer, 10 
very short, one third as long as 9 ; a smooth median dorsal line 
ending on 7; rudimentary dorsal hooks on 8 and 9; lateral 
spines on 6 to 9, incurved at tip, those of 9 about twice the 
length of segment 10. Superior and inferior abdominal ap- 
pendages twice as long as segment 10, laterals a little shorter 
than the others. 
Younger nymphs dredged from the bed of the stream differ 
only in size and in the shortness of the wing-cases. 
This nymph agrees in every point with the very careful 
description given by Hagen (’85, p. 262) for “ Gomphus adelphus 
(supposition ).” 
10. Gomphus spicatus Selys. 
In the collections of the State Laboratory are many 
examples of a nymph resembling graslinellus, all taken from 
shallow waters in Sand and Cedar lakes, northeastern Illinois, 
associated with that species, during June, August, and October. 
Dr. Ward has sent me another of the same species from a lake 
near Charlevoix, Mich. These nymphs we can properly assign 
to spicatus, imagos of which were collected at the same place, 
and which is one of the very few Illinois gomphids whose 
nymphs yet remain unknown.* The nymphs from Cedar Lake 
*Mr. Needham has since verified this supposition by breeding. 
