No. 39] ODONATA OF CONNECTICUT: COENAGRIONIDAE 71 



Enallagma doubledayi Selys 



Revue des Odonates ou Libellules d'Europe, 209: 1850. 



Nymph. — Gills (PI. i, Fig. 12) transparent, the tracheae almost 

 entirely without small branches, and the marginal spines extend- 

 ing well beyond tbe middle of the gills; dorsum of abdominal 

 segments 2, 3, and the base of 4 hairy; mental setae 3, and a 

 small fourth, laterals 5 ; lateral keels with a single row of spines 

 increased to two at the apices ; caudo-lateral margins of the head 

 rounded and with a few spines. 



Measurements: length of gills, 5.5-6 mm.; width, 1.25-1.5 mm. 



Notes made from a nymph reared by Dr. R. H. Howe, Jr. 



Adult, male. — Color blue and black. 



Head : blue and yellowish and black ; antennae brown ; ante- 

 clypeus and labrum yellow ; postocular spots small and a narrow 

 stripe caudad of the ocelli distinct. 



Thorax : black, blue and yellowish green ; mesothorax with a 

 broad black dorsal stripe, the stripe covering about one-third of the 

 katepisterna on each side ; legs black and yellow, the femora and 

 tibiae each with a black stripe on dorsum or cephalic surface, 

 wings with about 10 postnodal cross-veins in the front wing and 

 8 in the hind; M^ arising between the fifth and sixth postnodal 

 cross-veins in the front wing and between the fourth and fifth in 

 the hind wing. 



Abdomen: blue and black; terga i-io blue except a small basal 

 spot on the first, and apical spot and marginal ring on the second 

 to the fifth, apical half or two-fifths of the dorsum of the sixth ; 

 dorsum of the seventh except a narrow interrupted basal ring, and 

 the tenth, which are black; dorsum of segments 8 and 9 blue; 

 anal appendages similar to carunculatum and civile but the supe- 

 riors differ especially in dorsal view (Fig. 10, Nos. 25, 28). 



Female. — Abdomen with terga i to 10 with broad dorsal dark 

 stripes and basal interrupted rings, the lateral margins pale. 



Measurements: total length, male 28-31, female 30-31 mm.; 

 length of abdomen, male 22-25, female 24 mm.; length of hind 

 wings, male 17; female 18 mm. 



New England. — June 28-September 13. 



Group 3 Hageni-ebrium Group 



Enallagma ebrium (Hagen) 

 Synopsis of the Neuroptera of North America, 89: 1861. 

 Nymph, — Color usually green. 



Head : elliptical in outline, with a few spines on the caudo- 

 lateral surfaces; antennae with the first segment brown, also half 

 the second and one-third the third ; third segment longest, number 

 2 longer than i ; labium extending between pro- and mesocoxae 



