No. 39] ODONATA OF CONNECTICUT: LIBELLULIDAE 215 



Thorax : bronze or greenish metalHc, the venter dull brown ; 

 legs black except the coxae, which are brown ; middle and hind 

 femora with a ventral line of short spines from base to apex, the 

 line consisting of three to four spines abreast at base, but reduced 

 to a single one at apex ; tibiae with ventral keels as in Tetra- 

 gonenria, but the latter attached to the apical half of each and 

 never more than half as long as the tibia ; thorax with brown pile ; 

 wings (PI. XI, Fig. 2) clear, with only a touch of brown at the 

 extreme base of the hind wings ; membrane all dark, the hind 

 wings slightly yellow at base. 



Abdomen : black, terga i and 2 and part of 3 brown on sides, 

 and a yellowish area on 2 below the auricles ; apical three- 

 fourths of the dorsum of the third terga and dorsum of 4 to 10 

 black ; ventral area of 4 to 9 mostly yellow ; accessory and anal 

 appendages black ; inferior anal appendage bifurcate and each arm 

 cleft at the apex. 



Female. — Vulvar lamina about one-third as long as segment 9, 

 truncate, the median notch about half the depth of the plates, the 

 whole very similar to that of Gomphus descriptus (Fig. 20, 

 No. 13) but the tips are truncate. 



Measurements : total length, male 46-50, female 43-45 mm. ; 

 length of abdomen, male 31-32, female 30-37 mm. ; length of 

 hind wings, male 29-30, female 30-32 mm. ; length of stigma, 

 male and female, 2-2.5 rnm. 



The doubly bifurcate inferior appendage of the male is charac- 

 teristic of the species and genus. 



Connecticut. — Litchfield, 27 June, 1909, 28 June, 1918 (L. B. W.) ; 

 Cornwall, i June, 1925 (L. B. W.) ; Hamden, 7 June, 1927 (P. G.). 

 New England. — May 30-August 11. 



Genus Somatochlora Selys 



Nymphs. — Dorsal projections of segment 4 to 9 flattened, not 

 hook-like, sometimes wanting ; lateral spines of segment 9 usually 

 less than half the length of that segment, sometimes lacking alto- 

 gether ; hind margin of segment 9 strongly concave above ; con- 

 spicuous ventral pubescence on caudal margin of segment 9; no 

 frontal horn. 



Adults. — Arculus sectors separated at point of union with the 

 arculus; triangles usually with, but occasionally without cross- 

 veins ; subtriangle present, there being usually two cubito-anal 

 cross-veins in the hind wings ; area between Cu^ and M^ not 

 widened at margin of front wing; no dark spots present on the 

 wings (rarely with spot at base) ; compound eyes meeting on the 

 dorso-meson ; abdomen compressed, or not compressed ; color often 

 metallic. 



Adults of this genus are very rare in collections. Most of the 

 species are boreal in their distribution and their presence in Con- 



