106 



larvsB are distinguished from other aquatic insects bj' the possession 

 of a large protractile lower lip furnished with movable jaws ( palpi ) 

 at its extremity. Respiration in the larva and pupa is effected by 

 means of several caudal leaf-like gills, or by a branchial apparatus 

 in the walls of the hind part of the digestive tube. They are 

 predaceous when adult, feeding upon gnats, mosquitoes, flies, etc., 

 which they capture while flitting rapidly about. The larvae and 

 pupse also have the reputation of pi-^ying upon other insect^, and as a 

 rule this will probably be found true; but an examination of 

 several larv<e shows them to be in some cases largely vegetable 

 feeders, and possibly scavengers, the alimentary canal containing 

 numbers of desmids, diatoms, fragments of moulds, and a good 

 deal of material (probably slime ) gathered from the bottom for the 

 small organisms and the organic matter contained in it. The eggs 

 are dropped into the water as the females fly over it, or may be 

 attached to submerged plants. Members of one genus are said to 

 go beneath the surface and insert the eggs 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 Com- 

 mission 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 imma- 

 ture stages of a number of species were common. These latter 

 fall into four groups, which, for the purposes of this paper may 

 be characterized 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 Agridniua . 



Antennse 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 Gomphiua. 



Antennse 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. 



AntennfB filiform, of seven articles. Legs slender. Labium not 

 cleft. Labial palpi expanded and spoon-shaped, meeting along the 

 middle line. Includes numbers 9-12 Libelluliua. 



1. Agrion ramhurii, Selys. 



(Hagen, Syn. Neur. N. A., 1861, 76.) 



jj^A small dragon fly with narrow transparent wings and slender 

 body, with several of the hind divisions of the abdomen blue. 

 Possibly the adult of one of the two following. 



Common on the vegetation about Lily, Long, and Broad Lakes. 



