CORDULIA. 131 



2. C. linearis ! 



Cordulia linearis Hagen ! 



Obscure brassy-green ; labium luteous ; labrum and front fus- 

 cous, the front above, and the vertex brassy-green ; thorax small, 

 brassy-green, the sides fuscous, with a subaqueous tinge ; feet black, 

 base of the anterior femora luteous ; abdomen very long, slender, 

 the base compressed, inflated, brownish-black, segments 2 8 with 

 a basal, obsolete, yellow spot each side ; appendages black, the 

 superior ones short, the base cylindrical, arcuated, a small tooth 

 externally, the apex dilated, acutely bifid, before the apex is an- 

 other external tooth ; the inferior appendage a little shorter, tri- 

 angular, narrow ; wings hyaline, pterostigma small, black ; mem- 

 branule large, fuscous, the base pale ; anal angle of the male acute ; 

 nine antecubitals; 8 9 postcubitals; two discoidal areolets. 



Length 60 millim. Alar expanse 92 millim. Pterostigma 3 

 millira. 



Hob. St. Louis. 



3. C. tenebrosa. 



Libellula tenebrosa Say, Journ. Acad. Philad. VIII, 19, 4. 



Obscure brassy-green ; labium luteous ; labrum and front fus- 

 cous ; front brassy-green above ; vertex fuscous ; thorax brassy- 

 green, each side with two lines, and a point posteriorly, yellow ; 

 abdomen obscure brassy-green, the base inflated, then very slender, 

 behind the middle, fusiform ; superior appendages arcuated, a 

 tooth upon the middle superiorly, the apex abruptly incurved, 

 truncated; feet black; wings hyaline, pterostigma black; mem- 

 branule blackish, the base whitish ; interior, anal margin of the 

 posterior wings fulvo-fuscous. (From the description of Say.) 



Length 51 millim. or larger. 



Hob. Indiana. 



4. C. bifurcata. 



Cordulia bifurcata Selys' Collection. 



Hob. Canada ; Nova Scotia. Unknown to me, 



5. C. libera. 



Cordulia libera Selys' Collection. 



Hob. Canada. Unknown to me. 



