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



Measurements of a young nymph : total length, 4 mm. ; length 

 of abdomen, 2 mm. ; greatest width, 2 mm. ; length of wing- 

 cases, .25 mm. ; length of hind femora, 1.25 mm. ; length of median 

 lobe, 1.25 mm.; width, 1.2 mm. 



Described from a series of nymphs obtained from Illinois State 

 Natural History Survey through the courtesy of Dr. C. P. 

 Alexander, and specimens taken in Connecticut in different locali- 

 ties. Easily recognized by its hunchback appearance. 



Adult, male (PI. xx, b). — Color green and black, the thorax 

 and abdomen entirely bluish-pollinose, in older males. 



Head : green, black or dark brown as follows : spot on labrum, 

 mesal margins of the lateral lobes, cephalic surface of vertex, a 

 narrow line between vertex and front, and two dark spots on the 

 postgenae behind the caudo-lateral margins of the compound eyes. 



Thorax : entirely green or bluish-pollinose, the green individuals, 

 "frequently with dorsal carina antehumeral, humeral and two 

 indistinct lateral lines and some marks near the coxae black" f^ 

 prothorax with bilobed caudal margin, provided with a fringe of 

 long hairs ; legs black, the coxae and trochanters lighter ; tarsal 

 claws with a minute ventral tooth beyond the middle ; front coxae 

 flat with a dense fringe of hairs on the mesal ridge ; wings clear, 

 without opaque marks, slightly flavescent. 



Abdomen : entirely bluish-pollinose, or green and black ; terga 

 2 and 3 entirely green, 4-7 each with a black or brown spot occupy- 

 ing the caudal half of the dorsum ; terga 8 and 9 and sometimes 

 10 entirely black ; venter of abdomen brown ; superior anal appen- 

 dages green, about one-third longer than the inferiors ; hamules 

 of the second segment composed of a long, rounded, lateral lobe 

 and a slender mesal hook not quite as long as the lateral lobe ; 

 abdomen with but few hairs except on terga i and 2, and on 

 venter. 



Female. — Lacks the dark marks on the thorax: superior anal 

 appendages green ; caudal margin of eighth sternum entire, pro- 

 jecting ventrad a distance equal to half the vertical diameter of the 

 segment. Bluish or slate-colored forms do not occur in this sex ; 

 at least they have not been seen in Connecticut. 



Measurements : total length, male 44, female 38-43 mm. ; length 

 of abdomen, male 27, female 23-28 mm. ; length of hind wings, 

 male 32, female 30-31 mm. ; width of hind wings, male 9-10, 

 female 9 mm. ; length of stigma, male and female, 3-3.5 mm. 



Connecticut. — East Haven, 16 August, 1906 (P. L. B.), 30 July, 1921; 

 Hamden, 4 July, 1921, May, 1922 (P. G.). 

 New England. — May to September. 



''^Calvert. Trans. Am. Ent. Soc, xx: 265: 189.1. 



Genus Sympetrum Newman 



Nymphs. — Head: movable hooks of palpi small, usually seti- 

 form; lateral setae 7-13; mental setae 11-17; abdomen ovate. 



