192 IOWA ACADEMY OF SCIENCES. 



cells; two cross nervures and a series of cross yeinlets along 

 the hyaline costa always present. 



The genitalia seem to be very constant and very similar in 

 the different species and are consequently of little value as 

 specific characters. The last ventral segment in the female is 

 long, obtusely angled or rounding posteriorly. The last seg- 

 ment in the male is angularly excavated; valve large, round- 

 ingly pointed. Tne plates are broad and also convexly pointed, 

 similar in shape to the valve and about twice its length. 



The three species occurring at Ames agree in being two- 

 brooded, the broods occurring at about the same time, the 

 adults appearing in June and again in August, remaining less 

 than two months each time. The larvse, of the three species at 

 least, agree in being broadest at the middle, pointed at both 

 ends, light, with dark margins extending in front of the eyes 

 and meeting under the vertex. 



■PLATYMETOPIUS ACUTUS SAY. 



Jo^sus acutus, Say, Jour, Acad. Nat. Sci. Phlla., VI, p. 306, 1831; Compl. Writings, II, 

 p. 382, 1859. 



Platymetopius acutus, Uliler, Bull. U. S. Geol. and Geog. Surv., Ill, p. 473, 1877. 



This widely distributed form may be recognized by its remark- 

 ably, acutely, pointed vertex and narrow elongate face, together 

 with a row of black marked cross nervures along the costal 

 border and the finely irrorate elytra. Length, 5 mm. 



The larvEe resemble the adults in having the head elongate, 

 narrower than the pronotum. When full-grown they are about 

 four and one-half millimeters long by two millimeters broad 

 in the middle where they are the widest, and from which they 

 gradually and about equally, narrow to an acute point at either 

 end. 



Color: There is a broad dorsal light stripe including all the 

 vertex, parallel margined across the thorax where it is slightly 

 wider than between the eyes, constricted on the base of the 

 abiomen and again before the tip expanding on the disk of the 

 abdomen, and again on the extreme tip. This stripe is dis- 

 tinctly red on the center, shading out to creamy white on the 

 margin. The constrictions on the abdomen sometioaes com- 

 pletely dividing it into two spots, one on the disk and another 

 on the tip. A marginal black stripe extending the entire length 

 of the body on either side, meeting entirely below the edge of 

 the vertex in front, including numerous fine white maculations. 

 Below, inside the marginal stripe, creamy white. 



