LIFE HISTORIES OP THE ODONATA. 43 



Much which is now known is the result of chance ob- 

 servation, and the patient research of several seasons is 

 needed to throw light on the subject now under our con- 

 sideration. In their habits of flight the Odonata may be 

 divided into three groups, and these are nearly classifica- 

 tory in value, though not absolutely so. The first group, 

 comprising such genera as Agrion, Lestes, Calopteryx, et 

 al., usually known as the "hammer headed dragon flies" 

 (Plate YI., Figs. 4, 5), frequent the grassy margins of pools 

 and ponds, and the low bushes and shubbery by swamps. 

 Flving from stalk to stalk, darting after insects, they are 

 typically the hawks of the minuter insect world. The 

 second group, with true ^schna and Corduligaster as its 

 principal representative genera (Plate L, Fig. 2), are high 

 fliers and mighty knights of the upper air. They are the 

 largest of their suborder. They haunt the tall shuljbery, 

 the middle and upper portions of the trees, seldom come 

 within easy reach of the collector, and are less frequently 

 seen over the ponds and waterways. They are preemi- 

 nently the enemies of all juicy winged insects which leave 

 the lower levels in their flight. Seemingly, no insect is 

 too large to tempt them to an onslaught, and this rapa- 

 cious disposition is often the cause of many a midair 

 conflict between two or more of their own kind. Their 

 flight is more sustained than others of ihe Odonata; 

 they seem to be ab.solutely untiring. From early morn 

 until evening they are constantly on the wing, seldom 

 resting save to devour their prey, and not always stop- 

 ping for that. On account of their later hours it would 

 seem that this branch of the family are best suited for 

 an untiring warfare against the evening flying Dip- 

 tera. 



