114 CONNECTICUT GEOL. AND NAT. HIST, SURVEY [BuU. 



color of the legs, which are entirely dark in titia. The nymph of 

 titia is unknown. 



The genus contains another stream-inhabiting species in Con- 

 necticut, and this has only been collected in two localities. Strange 

 to say, both of these collections were made within a few days of 

 one another near the last of August, but it is known to fly late 

 in the summer, being reported from Illinois as late as October 22. 



Hetaerina americana Fabricius 



Entomologia Systematica, Supplement, 287: 1798. 



Nymph. — Color brown or greenish. 



Head : pentagonal ; proximal segment of the antennae nearly 

 as long as the remaining segments of each ; labium, with median 

 cleft hardly extending proximad of the articulations of the labial 

 palpi; palpi with three end-hooks and five or six (3 prominent 

 setae) small setae at the base of the distal segment or hook, caudo- 

 lateral margins of the head forming a blunt tubercle. 



Thorax: lateral margins of pronotum elevated, scalloped and 

 the margins produced at two points on each side. In younger 

 specimens the proximal half of each femur is dark brown, which 

 is followed by a light band beyond which the tip is again dark; 

 tibiae with three faint dark rings, and with dark bases and apices ; 

 apical half of third tarsal segment dark, claws dark. 



Abdomen: lateral keels not armed with spines though ending 

 in blunt tubercles on segments 8 and 9; lateral gills three-sided, 

 the median one flat and shorter than the lateral ; median gill with 

 dark axis and three dark cross-bands; lateral gills buflf-colored, 

 the three margins each with three dark spots and three to four 

 lighter colored areas. 



Measurements: length (excluding gills), 23 mm.; length of 

 abdomen, 12 mm.; length of lateral gills, 8.5-10 mm.; length of 

 metathoracic wing-cases, 6 mm. ; length of median lobe of labium, 

 4 mm.; width 1.3-3 ^^• 



Adult, male (PI. xvii. Fig. a). — Color bronze and metallic 

 green, bases of the wings carmine. 



Head : labium and labrum brown, the labrum with a black spot 

 at middle of the dorsal border; ventral margin of clypeus and 

 basal segment of the antennae also brown, the latter with a dark 

 spot at middle; remainder of the head bronze or metallic green. 



Thorax : bronzy green, the lateral sutures lined with pale color ; 

 mesopleural suture frequently black ; venter pale ; legs dark brown 

 to black; the coxae mostly pale, femora below and tibiae above 

 pale ; tarsi and claws black ; wings clear, the bases of each carmine 

 from base half way to nodus; hind wings brown along costal 

 border in front of the carmine color. 



Abdomen: metallic green, bronze or very dark brown towards 

 the tip ; the lateral margins of terga 1-6 inclusive and basal rings 



