PSEUDOXEUROPTERA. 75 



ures only 6 mm., and the tarsi are very long. These two species are our most 

 common representatives of this division of the Gomphinae. 



CORDULEGASTERIN.E. Our only genus is Cordulegdster, of which but few 

 species are found in the United States. 



CORDULIN.E. We have three genera of this sub-family, each of which is 

 well represented in our fauna. These are Macormia, Epithtca, and Cordttlia. 



LIBELLULIX/E. This sub-family is represented in our fauna by at least ten 

 genera. 



Family III. PERLID.E.* 



( )rder Pi. FA '< HTKKA of some authors, f 

 (Stont'-j! 



The family Pcrlidcc includes comparatively few species ; hut 

 members of it are common about any of our creeks. These in.- 

 are called Stone-flies because the immature forms are very abun- 

 dant under stones in the bed of streams. The adults are found fly- 

 ing about or resting upon herbage in the vicinity of water. 



The body is depressed, elongated, and with the sides nearly par- 



allcl (I -i! arc 1< 



ring, and many-jointed. The re unojual. the M-onl 



be l.iri;<-r. and 1: 



uid in H nl.il end of 



abdomen i- funiMn-d with two - 



, Pr1a: a : nc. 



f Plccflptera: f>!t(os ( -r !aitcI; // i wing. 



