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 al)dominal 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 grasluiellus, 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. 



