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



late, the points mostly blunt, and the dorsal marginal row of setae 

 of the median gill extending much beyond the middle ; three 

 narrow transverse bands sometimes occur just beyond the middle; 

 they are usually placed close together, but the bands may be 

 reduced in number or wanting. 



Measurements: length, 15 mm.; length of abdomen, 9 mm.; 

 length of gills, 1.8 mm.; width of gills, 1.8 mm.; length of 

 median lobe, 2.3, width, .8-1.6 mm. 



Adult, male. — Color blue and black. 



Head: face below the antennae pale except the postclypeus, 

 which is mostly black ; dorsum of head dark, the lateral ocelli with 

 a blue spot in front of each, the postocular spots large, cuneiform, 

 sometimes connected with the narrow blue postocellar stripe ; rear 

 of head pale. 



Thorax : blue and black ; pronotum mostly black with a large 

 blue spot on each median lobe, the caudal margin and the cephalic 

 also blue ; proepimera blue or pale below, black above. Meso- 

 thorax sometimes with a blue dorsal carina, the black on each side 

 about half the width of the anepisternum ; black stripe of the 

 mesopleural suture considerably narrowed caudad ; remainder of 

 the pleura except small spots near the wing-bases on the sutures, 

 blue ; femora dark above ; tibiae with a dorsal line including the 

 cephalic row of setae; tarsi brown, darker at tips; wings clear, 

 M^ usually arising between postnodal cross-veins 4 and 5 in the 

 hind wings. 



Abdomen: blue and black; terga 1-5 inclusive with a black 

 spot at base of i, subapical spot and apical ring on 2 and apical 

 spots and rings on 3-5 ; caudal half of 6 and three-fourths of 7 

 black; 8 and 9 blue; segment 10 black above, pale below. Anal 

 appendages (Fig. 10, No. 23) short, the superiors rounded when 

 viewed in profile, inferiors much longer, slender, acute and black 

 at their tips. 



Female. — Color blue and black, the blue, however, frequently 

 replaced with buff. Mesostigmal lamina black, with a pale spot 

 on the lateral angles, the cephalo-mesal angle of each not rounded 

 and hollowed out, as in cyathigcriun. 



Abdomen: as in cyathigerum (Fig. 11, No. 25). First tergum 

 as in male, second segment with an apical spot and dorso-mesal 

 line ; 3-6 with dorsal stripes widened subapically ; caudal half of 

 8 and all of the dorsum of 9 and 10 black; 8 variable in amount 

 of black. 



Measurements: total length, male 33-35. female 34 mm. ; length 

 of abdomen, male 26, female 26 mm. ; length of hind wings, male 

 19, female 21 mm. ; width of hind wings, male 4, female 4-4-5 mm- 



Though we have no very definite record of this species from Connecticut, 

 I have seen several specimens collected in the vicinity of Storrs which are 

 undoubtedly calverti. 



New England. — May 12-August 12. 



