No. 39] ODONATA OF CONNECTICUT: LIBELLULIDAE 237 



Williamsonia lintneri (Hagen) 



Bulletin de I'Academie royale . . . de Belgique (2), 45: 187: 1878. 



Adult, male. — Color brown or yellow and black. 



Head : face brown, vertex black or brown ; occiput and post- 

 genae black. 



Thorax : metallic green and brown, legs black, the femora with 

 very short spines; wings (PI. xvi, Fig. i) clear with the extreme 

 bases yellow ; triangles without cross-veins ; postnodal cross-veins 

 five to six in the front wings, antenodals seven to eight in the front 

 and five in the hind wings. 



Abdomen : terga 2 to 9 with pale apical transverse bands about 

 one-third the length of each segment ; anal- appendages black, the 

 superiors bluntly rounded at the tips and slightly swollen apically. 



Female. — Vulvar lamina consisting of two pointed lobes in 

 contact on the meson and a little more than half the length of the 

 segment; median incision about three-fourths the length of the 

 lobes. 



Measurements: total length, male 31-34, female 33-36 mm.; 

 length of abdomen, male 21-22, female 22-23 mm. ; length of hind 

 wing, male 21-22, female 22-25 mm.; width of hind wings, male 

 7, female 8 mm. 



This species probably occurs in Connecticut, but so far it has 

 not been collected. According to Dr. R. H. Howe, Jr., it flies only 

 in April and May, and may be taken in woods, usually near 

 sphagnum ponds. It has been found in several localities in 

 Massachusetts. 



New England. — April 30-June 21. 



Genus Dorocordulia Needham 



Nymphs. — Caudo-lateral margins of the head angular; spines 

 of abdominal segment 9 one-third as long as that segment. 



Adults. — With arculus sectors separate 10 point of union with 



arculus ; triangles of the front wings usually without cross-veins ; 



subtriangle absent ; area between M^ and Cu^ not expanded 



towards margin of front wing; bases of hind wings clear; color 



metallic. 



Key to Species 



Adults, Males 



1. Abdomen with segments 7-10 spatulately dilated; wider than the 



preceding segments ; .libera 



Abdomen with segments 7-10 not spatulately dilated; not wider _ 

 than the preceding segments lepida 



Females 



I. Abdominal segments 4-7 without conspicuous yellow spots on the 



cephalo-lateral angles; width of segment 9 more than 2 mm. . .libera 

 Abdominal segments 4-7 with conspicuous yellow spots on the 

 cenhalo-lateral angles; width of segment 9 less than 2 mm. ..lepida 



