62 STUDIES IN AMERICAN TETTIGONIIDAE (oRTHOPTBRA) 



Texas we find maximum sized individuals nearly twice as large 

 as New England specimens and at first glance apparently very 

 different. From west central Nebraska northward to south 

 central Montana we find the species holds a fairly uniform size. 



The most puzzling variation feature is in the length and curve 

 of the ovipositor. Over almost the entire range of the species 

 there is little variation in the relative size and curve of the ovi- 

 positor, which shows only very minor variations in depth, etc. 

 In the central area, however, and to a lesser degree in Montana, 

 we find a part or all of the females from certain localities possess- 

 ing ovipositors far longer, more robust and straighter than the 

 average type. This is the form called delicaium (gracile) by 

 Bruner and it and the more normal concinnum type were both 

 taken by him at West Point and Lincoln, Nebraska, while nu- 

 merous female specimens from Nehgh, Kearney, North Platte and 

 Haigler, Nebraska, and Billings, Montana, are nearer this type 

 than average concinnum, or intermediate between the two. No 

 other structural character stands the tests for correlation with 

 this ovipositor feature and it is impossible to sort the males before 

 us into two species, those, fourteen in number, for instance, from 

 Billings, a locality having no typical concinnum ovipositor among 

 its sixteen females, being quite inseparable from more eastern 

 specimens, while the males from West Point and Lincoln are 

 certainly one species, the male type of delicaium being the same 

 as dozens of others which are undoubted concinnum. The 

 explanation of this ovipositor development should, we think, be 

 looked for in the immediate environment in which the long ovi- 

 positor individuals occur, the fact that both have been taken at 

 one locality strongly suggesting this. 



Among the general structural variations we find the width of 

 the fastigium and the degree of divergence of the margins of the 

 same, when seen from the cephaHc aspect, to be quite variable, 

 while the degree of straightness or arcuation of the ventro- 

 caudal margin of the lateral lobes of the pronotum and the degree 

 of angulation of the caudal margin of the same are inconstant, 

 varying in nearly every series from a single locality. The form 

 of the stridulating field of the male tegmina is rather plastic, while 

 the male cerci show certain variational features in length, degree 

 of slenderness of the distal extremity and the strength of the 



