152 CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



EXTERNUM 



Fig. 23. Structural details of Gomphus fraternus, crassus and externus. 

 1-3, vulvar lamina. 6-11, occipital margins. 12-16, right superior anal 

 appendages in lateral profile. 17 and 18, Anal appendages, ventral aspect 

 (From Calvert, Ent. News, 12; pi. iii; 1901.) 



