IOWA ACADEMY OP SCIENCES. 
175 
as distinct species, and also to separate as distinct some forms 
hitherto included with other known species. 
Colorational characters in certain genera are of very little 
value, since it is found that summer broods and species occur- 
ring in shaded localities are pallid or unicolorous, while autumn 
broods or exposed individuals assume darker and more definite 
markings, often varying to black. 
Another feature of considerable interest and of value in the 
discrimination of species is presented in the fact that for a 
number of species there are distinct long and short winged 
forms with consequent variations in venation (usually given 
generic importance) the long winged condition apparently asso- 
ciated with a migrant habit. 
The grasses which have been more particularly under obser- 
vation during the season and which seem to have each its par- 
ticular jassid fauna, are: Blue grass {Poa pratensis)^ Anclro- 
pogon scoparius and provincialis, Elymus canadensis and virginicus^ 
Bouteloa hirsuta and cutipendula, Stipia spartea, Spartina cynosuro- 
ides, Sporobolus liookeri, heterolepis^ asper and cryptar<drus, Gliry- 
sopogon nutans, Muhlenbergia racemosa, diffusa and sylvatica, 
Bromus cUiatus and purgans', also a number of annuals, espe- 
cially the Panicums and Setarias. 
A statement of the known host plants accompanies the dis- 
cussion of each species. 
TETTIGONIA BIFIDA SAY. 
Journal Acad. Nat. Scl., Phila., IV, p. 313, 1831; Comp. Writings II, p. 387, 1869. 
This is a rather handsome little species, and its range of food 
habit seems to be more restricted than many of the others, it being 
found only on blue grass in shady places. The latter restric- 
tion confines it to wooded pastures, where it is perhaps almost 
as common though less universal than inimicus in open pastures. 
The adult is about six millimeters long, of greenish color , with 
circular alternate bands of black and white on the head and 
pronotum parallel to the border. The wings have seven black 
stripes, the outer one forking near the middle. 
Adults are first recorded for July 11th, and were most abun- 
dant July 14th, becoming gradually less numerous till the first 
of September, when they disappeared. While egg deposition 
must occur during July or August it has not been observed. 
The larvae observed July 2nd to 20th were about half the 
length of the adults, fully as broad, with the surface of the body 
