86 CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



tracheae more or less obscured ; gills usually with blunt points ; 

 length including gills 15-20 mm. 



Adults. — Head with or without postocular spots; wings with 

 12 or more postnodal cross-veins ; M, arising between the fifth 

 and ninth postnodal; width of stigma between C and R not 

 greater than its length ; stigma of male not remote from margin ; 

 dorsum of thorax with more or less brown or black, never entirely 

 metallic green, the caudal margin of female prothorax entire; 

 tibial setae longer than the intervals between their bases ; meso- 

 pleural suture usually with a black stripe immediately below; 

 abdominal terga 1-6 never red or yellow, usually black with 

 median stripes of brown or purple, or entirely black with pale basal 

 rings ; female without a ventral spine on segment 8. 



The Argias seem to be well differentiated in their habits at least 

 as far as Connecticut species are concerned. Violacea and trans- 

 lata are pond and small-lake species, and the nymphs may be found 

 around the borders of such ponds. The only place where trans- 

 lata has been found is a small reservoir supplying the town of 

 Wallingford, the adults being taken along the east shore, at the 

 base of a high hill which rises directly out of the water. The 

 entire east side of the lake is protected, and there is another hill 

 protecting the north end, the elevation of the pond itself being 

 about 300 feet. Moesta is a swift-stream species and is most fre- 

 quently found near such places. The eggs of all species are prob- 

 ably laid in dead plants or wood near the edge of the water. 



For literature dealing with adults, consult : 

 Calvert, P. P. Biologia Central! Americana, pages 69-72: 1901. 

 Also works of Carman (1917), Howe (1912), Kellicott (1899), Needham 

 (1Q03), and Williamson (1899). (See appended list.) 

 For literature dealing with the nymphs, see: 

 Needham, J. G. Bulletin 68, New York State Museum, pages 237-245 : 



1903. 

 Garman, P. Bulletin of the Illinois State Laboratory of Natural History, 



XII, 501-517: 1917- 



Howe, R. H. Memoir of the Thoreau Museum of Natural History. 11, 

 page no: 1921. 



Key to Species 

 Nymphs 



Labial palpi with a single weak seta on the proximal segment ; 

 gills broad at the tip, the margins parallel for a considerable dis- 

 tance; without light cross-bands and not coarsely spotted ..moesta 



Labial palpi with two or more setae on the proximal segment; 

 gills not with parallel margins, and usually coarsely spotted with 

 pigment 2 



Gills broadest beyond the middle, decidedly ovate, sharply pointed 

 and frequently with a V-shaped clear area near the apex . .violacea 



Gills not broadest beyond the middle nor sharply pointed at tips 



translata 



