54 DEAGONFLIES OF OHIO. 



on abdomen less sharply defined. The abdomen is 

 stout 8 and 9 somewhat expanded ; the appendages 

 are long, yellow, acute; the vulvar lamina nearly 

 as long as 9, divided to the base, branches nearly 

 cylindrical, pointed, apexes bent outward and upward, 

 clawlike. 



It has not been taken later than June 20 in Central 

 Ohio. 



GOMPHUS, Leach. 



This genus is well represented in our fauna; four- 

 teen species have been taken and a few more are sure to 

 be added in the future. 



Baron De-Selys has arranged the species in groups 

 defined as follows : 



I Group, (Indian). 



II Group. Front of thorax with six broad black 

 bands; 7, 8 and 9 much dilated; membranule moder- 

 ate. Anal appendages of the male black. 



III Group. Front of the thorax yellow with six 

 lines or bands, more or less broad ; segments 7, 8 and 

 9 somewhat dilated ; membranule very small ; anal ap- 

 pendages black, superiors as long as 9, inferiors almost 

 as long. 



IV Group. Front of thorax olivaceous, with 4 or 6 

 lines or bands, brown, more or less distinct; segments 

 7 and 8 moderately expanded ; anal appendages yellow 

 or light brown, superiors as long as 10, inferiors 

 nearly as long. 



V Group. Front of thorax with an interrupted, 

 mesothoracic semi-collar and two cuneiform spots 

 (stripes) yellow; sides yellow with two black rays, 

 confluent at two points; pterostigma short, black; 

 face mostly black; anal appendages brown, superiors 

 longer than the 10th segment. 



VI. Group. Front of the thorax black with two 

 antehumeral wide bands and a superior antehumeral 



