74 THE ACRIDIIDAE OF MINNESOTA 
der. Lateral lobes vertical or nearly so, often feebly tumid on the 
prozona, especially above, and marked with a piceous post-ocular band, 
crossing the prozona or the whole pronotum, frequently broken or 
maculate. Prosternal spine variable but always prominent ; mesosternal 
interspace generally much longer than broad; rarely transverse, but 
never broader than long; metasternal lobes generally attingent or sub- 
attingent. Tegmina always present but variable. When abbreviate 
they may be lateral, attingent, or overlapping, Sometimes shorter or 
longer than the pronotum, but usually about the length of the prono- 
tum and apically more or less acuminate. They may also be fully 
developed, when they equal, surpass, or fall a little short of the tips 
of the hind femora, and taper more or less, but very gradually, and 
are apically rounded. Hind femora moderately long and slender; 
hind tibiae with a variable number of spines (9 to 14) in the outer 
series, rare exceptions have but eight. Abdomen generally more or 
less compressed, the extremity in the male more or less, sometimes 
strongly, clavate, usually considerably recurved; subgenital plate of 
variable form but always with the lateral margins ampliate at base 
and with no distinct apical tubercle, though frequently apically pro- 
duced or subtuberculate and frequently tumescent; the cerci exceed- 
ingly variable in form, often enlarged apically, nearly always lamellate, 
never styliform, generally incurved, and of about the length of the 
supra-anal plate; furcula usually developed, though quite variable in 
extent and form; ovipositor of female generally fully exserted. 
This comprises the largest genus in the Acridinae and the one 
most widely distributed in North America, although it is apparently 
confined to this continent, where it is represented by approximately 
150 species. These species are usually very similar in size and color 
and the differentiating characters are based largely upon the cerci, sub- 
genital, supra-anal plates, and furcula of the males. In a few instances 
differentials have been worked out for the females but in general their 
classification can be best made upon comparison with accurately named 
material. Many species occur in both long-winged and short-winged 
forms and as there is in most species considerable variation of the 
cerci and furcula the classification of any large series of this genus 
presents an extremely difficult problem. Possibly because of this fact 
“new species” have multiplied and the records of many species have 
been so confused that the range of species is in some cases almost 
hopelessly clouded. To the writer, from observations in the field, it 
appears clear that in some cases species have been based upon too 
scant material or upon a few specimens from the extreme forms of 
variant species. The following key, which is based upon Scudder’s 
Revision of the Melanopli (Proc. U. S. Natl. Museum, Vol. XX), 
modified somewhat in order to separate more easily Minnesota speci- 
