No. 39] ODONATA OF CONNECTICUT: COENAGRIONIDAE 45 



including the postcoxal areas greenish yellow, the metapleural 

 suture, however, sometimes black ; legs striped, the femora black 

 or dark above, the dorsal stripes of the tibiae narrower ; tarsi and 

 claws pale, darker at apices ; wings with 6-9 postnodals, and Mj 

 usually arising between the third and fourth postnodal (occa- 

 sionally beyond) in the front wing and between the second and 

 third in the hind. 



Abdomen : shining black or green, and yellowish green, dorsum 

 of terga 1-7 black or green, with pale basal rings and lateral 

 margins ; dorsum of 8 and 9 blue with dark lateral dashes, one 

 on each side, the dash extending about three-fourths the length 

 of the segment from the cephalic margin; anal appendages (Fig. 

 10, No. 4) composed of flattened, almost vertically placed supe- 

 riors, the inferiors longer; dorsum of segment 10 strongly ele- 

 vated and with two small tubercles. 



Female. — Color orange and black or entirely black, tip of abdo- 

 men sometimes with blue ; all markings often obscured with pollen 

 in older specimens. Mesostigmal plates and hind margin of 

 pronotum as in Fig. 11, No. 12. 



Orange variety. — Head and thorax similar to the male except 

 that all pale marks are orange instead of greenish yellow ; post- 

 ocular spots large, sometimes connected with pale color of occiput ; 

 femora usually pale above ; abdomen with first two, and four- 

 fifths of the third terga orange, remaining terga black above. 



Black variety. — Similar to the male except that the dorsa of all 

 terga are black. 



Blue-tipped variety. — Greenish yellow of the male replaced by 

 pale blue, the dorsa of terga 8 and 9 marked with bright blue, in 

 some similar to the male, with a black stripe on each side ; in 

 others with irregular blue spots above. 



The black and orange varieties of the female are regarded by 

 some as different stages in the development of the insect, and the 

 blue-tipped form may also represent an early stage. A majority 

 of the specimens taken in midsummer will be found to be the black 

 or pollinose variety, in which state it is necessary to rely on wing 

 veins and the mesostigmal plate for determination. The plate in 

 all varieties is black, with pale lateral angles, and the caudal 

 margin elevated and forming a conspicuous ridge the full width 

 of the plate (Fig. 11, No. 12). The caudal lobe of the pronotum 

 is also different from Enallagmas, being provided with a double 

 margin of peculiar form. 



Measurements : total length, male 23-30, female 26-30 mm. ; 

 length of abdomen, male 18-25, female 23-24 mm.; length of 

 hind wings, male 11-17, female 16-17 mm.; width of hind wings, 

 male 2-3.5, female 3-3.5 mm. 



Connecticut. — South Manchester, 3 August, 1896 (W. C. S.) ; Mount 

 Carmel, 2^ June, 1902 (E. J. S. M.) ; Poquonock, 9 July, 1903 (W. E. B.) ; 



