18(33.] 
211 
taken by me at the end of Augast on Rock River, Ill. There is, it is 
true, a small but distinct tubercle above on the posterior base of the 
median laminiform tooth of the appendage, which is not specially 
mentioned in the Monographie; but as this tubercle exists in both my 
other species of this subgroup, it probably exists also in americana. 
The carmine-red basal spot on all the 4 wings extends about f the way 
to the nodus, or 11—12 cellules beyond the quadrilateral in the front 
wing and 8—9 cellules beyond the quadrilateral in the hind wing. 
Now americana % is described as having the carmine-red spot reach 
only I the way, instead of f the way, to the nodus; and in a S speci¬ 
men sent me by Mr. Uhler, which however as it has lost most of its 
abdomen cannot be identified with certainty, it reaches in the front 
wing 5 cellules beyond the quadrilateral and in the hind wing 3. I 
observe, however, that in rupamnensis % n. sp. there is a variation of 
2 and 5, and in pseud americana % n. sp. a variation of 2 and 4 cellu¬ 
les in the extent of the basal spot in the front and hind wings respect¬ 
ively; and as a character which is variable in one species may gene¬ 
rally, I think, be assumed to be more or less variable in closely allied 
species, we may disregard in this specimen the unusual extent of both 
basal spots, being about 6—7 cellules of overplus. Again, in ameri¬ 
cana % the basal spot is described as “ leaving the costal margin free 
almost for its whole extent” in the front wing, and “ leaving the post- 
costal margin free from opposite the arc” in the hind wing; (Monogr. 
p. 132,) and such is the case also in the specimen from Mr. Uhler. 
In my S the spot on the front wing leaves the costal margin at ^ its own 
length from the base of the wing; and that on the hind wing leaves the 
postcostal margin at f its own length from the base of the wing; the other 
two margins are touched by the spot throughout its entire length. 
But in these points, too, I find very considerable variation in the above 
named two species. There are also some other less important and 
equally variable characters in which our insect dilfers from the descrip¬ 
tion, viz. l.sif. The entire second joint of the antennae is brown, in¬ 
stead of being “ brown at each end;” but it is also uniformly brown 
in the Uhlerian specimen of americana. 2ind. The pterostigma is 
black, instead of “reddish-brown” in the mature % and “yellow” in 
the immature 'S • 3r<7. The epistoma is brassy-green, and the top of 
the head and the dark parts of the thorax coppery-red, as is also the 
