176 Illinois State Lahoratonj of Natural History. 



neath the surface and insert the e^gs in the stems of plants. 

 The young are common objects in the stomachs of fishes. The 

 adults were not common about the pools in which the Fish 

 Commission work was done. An occasional large species with 

 clear wings was seen, and a small, slender-bodied form was 

 noted as common about Lily, Long, and Broad Lakes. These 

 were the only winged dragon flies seen. In the water, on the 

 contrary, the immature stages of a number of species were 

 common. These latter fall into four groups, which, for the 

 purposes of this paper may be chacterized as follows : 



Antennae filiform, of seven articles. Legs slender, not 

 suited to digging. Abdomen long, cylindrical, terminating in 

 three large, flat, leaf-shaped respiratory appendages. Includes 

 numbers 2 and 3 , Agrionina. 



Antennae stout, of four articles, the distal one rudimentary. 

 Legs stout, suited to digging; tarsi of two anterior legs of two 

 articles; tarsi of posterior legs of three articles. Labium not 

 cleft. Includes numbers 4, 5, and 6 Gomphina. 



Antennae filiform, of six or seven articles. Legs slender; 

 all the tarsi of three articles. Labium with a narrow median 

 cleft. Labial palpi not expanded and spoon-shaped. Includes 

 only numbers 7 and 8 -/Eschnina. 



Antennas filiform, of seven articles. Legs slender. Labium 

 not cleft. Labial palpi expanded and spoon-shaped, meeting 

 along the middle line. Includes number 9-12. .. .Libellulina. 



1. Agrion raDibnrii^ Selys. 



(Hagen, Syn. Neur. N. A., 18G1, 76.) 



A small dragon fly with narrow transparent wings and 

 slender body, with several of the hind divisions of the abdo- 

 men blue. Possibly the adult of one of the two following. 



Common on the vegetation about Lily, Long, and Broad 

 Lakes. 



2. Agrionina, nymph. 



A larva about .72 inch long; common in Long Lake. 

 Chiefly brownish black. A pale, transverse band between the 

 eyes, and a ring of minute, pale dashes at the hind margin of 



