70 IOWA ACADEMY OF SCIENCES. 



white spots on the costal margin and in the apical cells; below, 

 lower half of face and the anterior coxae creamy yellow, upper part 

 of face and the abdomen, except the margins of the segments, black. 

 A variety of the male is colored like the female. 



Genitalia; ultimate ventral segment of the female twice longer 

 than penultimate, posterior margin slightly produced in the middle, 

 pygofers twice longer than wide, much exceeded by the ovipositor, 

 which is as long as the rest of the abdomen; male, valve wanting, 

 plates together, about half as wide as the ultimate segment, nearly 

 half longer than wide, roundingly narrowing to the middle, then 

 nearly parallel margined to the rounding points. 



Length $ 7mm., $ 4 mm.; width 9 2-2. 25mm., $ 1.5mm. 



Described from eleven specimens from Fort Collins, Colo., 

 and two from Stratton, Neb. 



This is a very interesting polymorphic species, exhibiting 

 two forms in the female, differing in wing length, and two in 

 the male, in color. It has bean found only on a single grass, 

 Sopordbolus crypfandrus, to which the larvae and adults seem to 

 be strictly confined. The larvae appear the last of April, and 

 the adults about the 1st of June. 



The short-winged females are large, sluggish and clumsy, 

 and either remain quiet on the stems or simply drop to the 

 ground; in either case the grayish-brown spots imitate the rust 

 on a dead leaf so well that, they are difficult of detection; the 

 long- winged ones are narrower, more active, and readily fly, 

 their agility, combined with their scarcity, making them a 

 highly desirable capture. The males are all long-winged, 

 small and active; the majority of them are nearly black, while 

 a few mimic the females in color; in either case they rely on 

 their activity and their harmony with the ground on which 

 they light for protection. 



PARABOLOCRATUS FIEB. 



Three species of this genus are now known from the U. S. ; 

 they all occur in long and short-winged forms, in the females, 

 and only long-winged forms in the males. They may be sepa- 

 rated as follows: 



A. Male vertex with the margin foliaceous, lined with black 



beneath. Elytral nervures not distinctly fuscous 



viridis Uhler. 



AA. Male vertex with the margins sometimes acute, but not foli- 

 aceous, elytral nervures more or less fuscous. 

 B. Vertex with the margins acute in the female, slightly 

 so in the male, male elytra yellowish-green, nervures 



slightly fuscous; males over 5mm. in length 



flavidus Sign. 



