Xo. 39] ODONATA OF CONNECTICUT: COENAGRIONIDAE 69 



segments 2-9 with from 9-20 on each. Gills (PI. 11, Fig. 8) 

 lanceolate, colorless and usually without pigment except in the 

 smaller tracheae, the margins very transparent ; dorsal marginal 

 spines of the median gill extending less than half the length of the 

 gill from its base; ventral row of lateral gills slightly longer. 

 Female ovipositor extending to the middle of the tenth abdominal 

 segment. 



Measurements: length 15 mm.; length of abdomen 10 mm.; 

 length of gills 6 mm. ; width of gills i. 8-2.1 mm. ; length of meta- 

 thoracic wing-cases 4.5 mm.; length of median lobe 3.1 mm.; 

 width of median lobe .8-2.3 mm. 



Adult, male (PI. xvii, c). — Color blue and black. 



Head : blue and black ; mouth-parts bufif ; antennae dark brown 

 or black; postclypeus with a shining black spot, margins pale; 

 anteclypeus shining yellow or blue ; labrum shining yellow or blue, 

 with a small, black dorso-mesal spot; area above the clypeus to 

 the antennae pale ; remainder of front and the vertex dull black ; 

 postocular spots oval or subcuneiform, the pale line behind the 

 ocelli indistinct; occiput and postgenae yellow, except the area 

 caudoventrad of the postocular spots. 



Thorax : blue and black ; pronotum black, except the pale 

 cephalic and caudal margins and a spot on each median lobe on 

 the lateral margins ; proepimera black above, pale below ; meso- 

 thorax, lateral half or third of the mesostigmal plates usually 

 yellow ; dorsal black stripe covering nearly half of each anepi- 

 sterna; pale stripe of anepisterna broadest dorsad of the kat- 

 episterna and extending nearly to the wing bases. Mesopleural 

 black stripe of the suture narrowed cephalad of the wing-bases, 

 and broadest caudad of the katepisterna, the dorsal third of which 

 is covered by the stripe. Metapleural suture with a black spot 

 cephalad of the wing bases, remainder of the pleura blue and 

 buff ; postcoxal areas buff, becoming pollinose ; legs striped, the 

 coxae and trochanters pale, the femora with black on the dorsum, 

 the tibia with about half the dorsa black; tarsi and claws pale, 

 darker at tips; front wings with 9-13 postnodal cross-veins, the 

 vein M2 arising between the fourth and sixth of these. 



Abdomen : blue and black, the cephalic terga largely blue, the 

 caudal ones darker and frequently pollinose with age; terga 1-6 

 inclusive blue except a basal spot on the dorsum of i, and shield- 

 shaped apical spots on 2-6 ; black of 6 occupying half the dorsum 

 or more ; that of 2 to 5 about one-fourth ; terga 7 and 10 black, 

 except the lateral margins, 8 and 9 blue ; anal appendages ( Fig. 

 10, Nos. I, 5, 29) short, the superiors blunt and with a narrow 

 cleft or notch ventrad of the dorso-apical angle ; inferiors usually 

 black and shorter, the black tips directed caudo-dorsad and fre- 

 quently in contact with the superiors. 



