WILLIAMSONIA 199 
stigma black; membranule dark gray. Abdomen greenish above, becoming 
blackish posteriorly; segment 2 yellow at the sides, the pale area being diagonally 
divided by fuscous 3 yellow at base of sides and along the infero-lateral margin. 
This species is common about the boggy borders of small upland 
lakes, where it flies in midsummer during sunshine, gaily in and out of 
the little bays and over the shallows. The nymphs inhabit the edges, 
commonly under the overhanging turf, and clamber up projecting roots 
and stumps to transform. They usually leave their cast skins less than 
a foot above the water. 
168. Dorocordulia lepida Hagen 
Hag. ’71, p. 264: Mtk. Cat. p. 127: Howe 719, p. 54: Garm. ’27, p. 238. 
Length 38 mm. Expanse 62 mm. N. Eng., N. Y., N. J. and Pa. 
A small greenish species, similar to the preceding, but with abdomen less 
spatulate, more nearly cylindric. The face is green but the clypeus is whiter 
and the yellow spots on the lateral aspect of the frons are larger. The vertex 
is yellowish at the summit, and the occiput, in the middle. The thorax is green 
underneath its hoary haircoat, with only the depths of the lateral sutures 
blackish. Legs black. Wings hyaline, stigma black, costa obscure. Abdomen 
with yellow basal side spots on the middle segments, and double yellow larger 
areas on the sides of segments 2 and 3. Segments 8, 9 and 10 and appendages 
black. 

shurtleffi 
35. WILLIAMSONIA Davis 
(Bull. Brooklyn Ent. Soe. 8: 98, 1913) 
Very small Cordulines and very slender. All the triangles are without 
cross veins. The anal loop is scarcely widened at the tip. The lateral 
margins of the second abdominal segment in the male are produced 
backward in a long hairy genital lobe; the auricles are minute, and the 
inner margin of the hind wing is scarcely notched. 
The nymph is unknown. 
KEY TO THE SPECIES 
Adults 
1 Abdomen with segments 2 to 9 ringed with yellow at apex...... 
ae aS RPE SR MEN eA VEL UE WR eM Ack lintneri, p. 200 
Abdomen with segments 2 to 9 not with yellow at apex........ 
OME MNS 5s ats cg MR es GRETA Seana Ana ea ee fletcheri, p. 200 
