2IO CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



The nymphs of probably the most common species in Con- 

 necticut are very active in late fall and early spring along the 

 edges of ponds and streams, usually in vegetation of some kind. 

 The adults appear very early in summer and often congregate in 

 droves in favorable locations away from the water. A large 

 number of the species cynosura were seen at one time about a 

 clump of sumach. On investigation it was found that they were 

 feeding upon a species of Psyllid, Calophya nigripennis Riley, 

 which were very abundant on that host. The eggs of Some 

 species, at least, are known, and they are reported (Needham 

 1901) to be laid in strings and draped over vegetation in the 

 water. 



Key to Species "^ 

 Adults, Males 



1. Superior anal appendages seen in lateral profile with a sharp sub- 



median inferior tooth spinigera 



Superior anal appendages without a sharp submedian inferior tooth 2 



2. Superior anal appendages with a tubercle above, near tip canis 



Superiors without a tubercle above near tip 3 



3. Front with a dark T-spot above (mono) 



Front without a dark T-spot above cynosura 



Females 



1. Front with a T-spot above 2 



Front without a T-spot above 3 



2. Vulvar lamina not 2 mm. long or less (morio) 



Vulvar lamina 3 mm. long ' spinigera 



3. Vulvar lamina less than 2 mm. long cynosura 



Vulvar lamina usually 3 mm. long canis 



Tetragoneuria spinigera Say 

 Bulletin de I'Academie royale . . . de Belgique (2), 31: 269: 1871. 

 N5aiiph. — Color of exuviae uniform brown. 

 Head : labium extending between the procoxae and mesocoxae ; 

 mentum with 7-9 setae on each side, the distal margin extended 

 considerably on the meson and forming an obtuse angle, the distal 

 margin thinly spinose ; labial palpi with 6 lateral setae, the mesal 

 margins each with 6 rounded teeth about as wide as long, each 

 having 3-4 heavy spines and several smaller ones ; labrum with a 

 fringe of hairs on the ventral margin ; front and vertex dark 

 brown with a paler T-spot between the antennae ; mesal angles 

 of the compound eyes rounded ; a small setose elevation on the 

 vertex behind each caudo-mesal angle of the eyes; caudo-lateral 

 margins of the head rounded. 



^^ Semiaquaea differs from the species given in the key in having the wings clouded 

 distad as far as the nodus. Nymphs of the different species are so closely related that 

 no attempt will be made to construct a key for their separation. Canis is said to 

 possess much shorter spines on segment 9 than any other species, but this is uncertain 

 since the species has not been reared. 



