180 DRAGONFLIES OF NORTH AMERICA 
138. Tetragoneuria cynosura Say 
Say ’39, p. 30: Mtk. Cat. p. 125: 11, p. 104: Davis ’13, p. 23: Whed. 14, p. 97. 
Syn: lateralis Burm., var. basiguttata Selys, complanata Ramb., costalis Selys, 
Semiaquaea Burm., indistincta Morse. 
Length 38 mm. Expanse 58 mm. Me. and N. D. to Fla. and La. 
This is a brownish, hairy, non-metallic dragonfly of very great agility. Face 
yellowish; frons with a black band before the eye, and occasional traces of a 
T-spot before it on the frons. Thorax brownish, clothed with gray hair; sides 
with an obsolete yellow stripe. Legs blackish, the front ones darkest. Wings 
hyaline with brown bases, only the wing roots brown in the fore wing; hind 
wing brown as far as the triangle, and several droplets of brown at vein con- 
junctions beyond; the brown area generally fenestrate with hyaline before the 
arculus and behind the anal crossing. 
The aerial prowess of these insects had been noted by all observers: 
It is an insect of splendid aerial powers, and on sunny days is seldom seen to 
rest. (Walker ’08, p. 19). 
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 30 or 40 feet from the ground and at long intervals 
resting for a moment upon the boughs of a tree. When over the water they fly 
lower but dart with extreme rapidity along the reedy margins of some promon- 
tory (Whedon ’14, p. 97). 
ery 
cynosura spinigera canis selysit 

hovers over the water but rarely alights; very pugnacious, attacking 
and driving away Gomphus and even Aeschna. (Wilson ‘09, p. 656). 
On May 28 ’10 there was a remarkable gathering of this species, together with 
an occasional spinigera and semiaquea, along the road leading from Newfound- 
land, N. J. to Cedar Pond. The air was full of these dragonflies and on one small 
dead bush we counted 22 individuals and there were other bushes and stems of 
plants that also had a great many resting upon them. (Davis ’13, p. 23.) 
Williamson (’05) has observed the egg laying habits. The female 
extrudes her eggs and carries them in a pellet underneath the abdomen. 
The egg mass is held during flight by the long and widely forked sub- 
genital plate. The female carries it for a long time ‘‘evidently not look- 
ing for a point for ovipositing.”’ 
The flight of the female under observation became more deliberate and she 
approached nearer the surface. Suddenly the tip of the abdomen swept the 
water as rapidly as though the species were a Libellula or Tramea. Delay would 
be fatal here, for the pond is filled with hungry species of the bass family, which 
