218 ENTOMOLOGICAL NEWS. [May, '16 



gree of aberration from the normal type would prove to be 

 difficult to determine. As the matter stands, however, 

 scarcely anything of use can be found in the literature on the 

 genitalia of the numerous described species. Those of dis- 

 tinctive marking and coloration can usually be located, but 

 among the descriptions of the plain green forms (with or 

 without minute dots on the wings and with immaculate an- 

 tennae and no dark lines on pronotum or tegmina) seldom 

 anything of diagnostic value may be found. It is evident that 

 the types of the species, thus insufficiently described, must be 

 studied before the nomenclature of the plain forms of the 

 genus may be put on anything like a secure basis. In the 

 meantime, we only urge that, in studying such material, the 

 male genitalia be always carefully considered. The females 

 offer scarcely any genital features ; as a result, while the sexes 

 of the more distinctively colored specimens are rather easily 

 associated, those of some of the plain green species are difficult 

 in the extreme. 



MALE GENITAL CHARACTERS. 



The supra-anal plate in different species has the distal mar- 

 gin weakly convex, transverse, weakly angulate-emarginate 

 or strongly emarginate. Though constant 'in most species, 

 this margin varies in at least one very widely distributed form 

 from very weakly convex to distinctly obtuse-angulate emar- 

 ginate. The cerci are of subequal width throughout with apex 

 broadly rounded, distinctly tapering with apex sharply 

 rounded, or tapering to last joint which is slender and elong- 

 ate, while differences in length are also found in different spe- 

 cies. Very little variation is found in these appendages in the 

 majority of species, but in one widely distributed form not 

 only do they vary in length, but also in proportionate diam- 

 eter. The subgenital plate has the distal margin between the 

 styles transverse, triangularly produced with apex rounded, 

 triangularly produced but weakly emarginate mesad, and 

 weakly convex to strongly produced sinistrad and so asym- 

 metrical in different species. Very little variation is found in 

 this feature. The styles are elongate cylindrical, varying 



