REHN AND HEBARD * 47 



length, heaviness, degree and regularity of curvature and the size 

 and direction of the apical tooth with which they are always 

 armed. Characters of the ovipositor are few, differences in the 

 degree of sharpness of the upward curvature being sometimes im- 

 portant, particularly in separating I. elegans from /. elegans con- 

 suetipes, which latter geographic race has the ovipositor not nearly 

 as sharply bent upward. The margins of the ovipositor do not ac- 

 quire serrations until the mature condition is reached; these serra- 

 tions are in the shape of isosceles triangles, their apices frequently 

 blunt and rounded. The subgenital plate in the females presents 

 several distinct forms as treated in the generic description, but a 

 certain amount of specific variation is found and it seems advisable 

 to use this character only in conjunction with a general study of 

 each species. . 



Notes on Tegmina. — The venation of the tegmina does not appear 

 to be of importance as a source of group or specific characters. 

 The tegminal outline is of the greatest use in separating the genus 

 into two groups and is also important in separating 7. elegans from 

 its geographic race, elegans consuetipes. Variation in tegminal 

 length is pronounced in I. intermedia alone. In the other species 

 of the present genus the tegminal length is found to vary to a de- 

 cidedly limited degree. 



Notes on Color Pattern. — In the present group the color pattern 

 is important and affords, in a number of cases, valid specific char- 

 acters. In the normally brown species which are streaked and 

 speckled with darker, /. tolteca, intermedia, holivari, phthisica and 

 gracillima, we find that the first three species bear meso-dorsad on 

 the second and third dorsal abdominal segments a distinctive and 

 striking trapeziform spot; in the remaining two species the sides of 

 the median and first four dorsal abdominal segments are more ir- 

 regularly and much less strikingly marked with dark brown. I. 

 prasina is distinguished from all of the other species by its apple 

 green coloration and the fact that the fourth abdominal segment 

 bears on each side a conspicuous small rounded black spot or dot, 

 situated near the caudal margin of the segment. The only species 

 of the genus having the dorsal abdominal segments immaculate are 

 /. apache and ahhreviata; the former species is immaculate chro- 

 mium green in general coloration, the latter is the only species which 

 is practically immaculate in general coloration yet exhibiting both a 



TRANS. AM. ENT. SOC, XL. 



