1929 ] On Certain Forms of Common American Butterxies 29 
plant, as for instance the moist condition up to the time of 
flowering and the dry condition after flowering or toward 
the end of the growing season. 
Wet and dry forms are more or less independent of tem- 
perature. For instance, all the forms of Eurymus eurytheme 
about Washington in the summer are clear yellow on the 
under surface of the wings and in the autumn are heavily 
infuscated. But wet forms seem to be very sensitive to dessi- 
cation in the extreme cold of winter if they hibernate as 
adults or as pupae. 
Here as elsewhere there is to be remarked a considerable 
difference in habits between wet and dry forms, the latter 
being always the more active. 
Junonia coena. — The common buckeye occurs in the Dis- 
trict of Columbia in two quite different forms. 
In the usual form the fore wings measure about 27 mm. 
in length in the females and about 24 mm. in the males. The 
ground color above is a medium brown. Beneath the ground 
color of the hind wings and of the apex of the fore wings is 
light gray, usually slightly tinged with buff, and there are 
two conspicuous oval black spots about as broad as, or nar- 
rower than, an interspace which are narrowly ringed with 
buff not far from the outer margin of the hind wings. 
The wings are dry and brittle, and nearly all the individ- 
uals caught are nicked or more extensively damaged. 
This form is exceedingly alert and active and a very 
strong flier. If alarmed it flies rapidly away, often not paus- 
ing before it is out of sight. It is fond of flowers, especially 
white flowers rising well above the grass, and for resting it 
always chooses the summit of a tall weed or of a tall dead 
stem or the bare ground from which it can easily dart away 
in any direction. 
It is found throughout the District, most abundantly in 
dry open country, and is not infrequently noticed in the 
parks and about the streets of Washington. 
In the other form the fore wings are about 30 mm. long 
in the females and about 28 mm. long in the males. On the 
upper surface the ground color is dark and the brown of the 
fore wings and of the outer half of the hind wings some- 
times shows dark green metallic reflections. On the under 
