PRELIMINARY NOTES ON THE ODONATA. 97 
FAMILY LIBELLULIDAE. 
SUB-FAMILY CORDULINAE. 
Genus Epicordulia Selys. 
E. princeps Hagen. Two males of this expert flier were brought 
down by the net on the shore of Lake Madison, August 10, 1914. It 
was seen on this one occasion only and but four individuals, three 
males and one female, were counted. The shore here was covered with 
tall weeds and bushes, with trees a few yards back and a Sagittaria bed 
in the shallow water in front. Libellula pulchella and Plathemis lydia 
were the only other large dragon-flies present. Wilson captured one 
male at Stillwater, July 16, 1907. 
Genus Tetragoneuria Hagen. 
TI. cynosura Say. Wilson’s records of this form are from Lake 
Phalen, St. Paul, and Hastings, July 8 and 12, 1907. He found it 
common. About the lakes in Dickinson County, Iowa, it was fairly 
numerous during the latter half of June and the whole of July 1909. 
T. cynosura semiaquea Burm., given specific rank by some writers, 
was also present. 
These insects are extremely quick and tireless on the wing. They 
often dart back and forth across some glade or small clearing near the 
shores of the larger lakes, keeping at a height of thirty or forty feet 
from the ground and at long intervals resting for a moment upon the 
upper boughs of a tree. When over the water they fly lower but dart 
with extreme rapidity along the reedy margins of some promontory. 
T. spinigera (Selys). Taken at Lake Amelia, Minneapolis, Beaver 
Lake, St. Paul, Hastings and Stillwater by Wilson, July 6-16, 1907. 
Quite abundant. 
Genus Dorocordulia Needham. 
D. libera (Selys). “Several seen flying over small streams; hard 
to catch but both sexes secured.” Walson, Stillwater, July 16, 1907. 
This beautiful species seems limited to the Transition Zone. 
SUB-FAMILY LIBELLULINAE. 
Genus 7ramea Hagen. 
T. lacerata Hagen. No specimens of this or other members of the 
genus have been actually taken within our limits, but the writer has 
spent hours on several occasions in unsucessful attempts. From June 
10, to July 15, 1913, two or more species of Tramea were quite com- 
mon about the ponds in the sand bars of the flood plain along the Min- 
