52 
Psyche 
[April 
NORTH AMERICAN DIXIDJE. 
By 0. A. JOHANNSEN. 
Cornell Universty, Ithaca, N. Y. 
Some years ago I published a key to the species of Dixa 
(Bull. New York State Museum, 68:431, 1903) based largely 
on the color characters given in the descriptions. Through the 
kindness of Mr. Nathan Banks I have recently had the oppor- 
tunity to compare my specimens with the Loew types in the 
Museum of Comparative Zoology at Cambridge, and now offer 
a new table which includes three new species. 
A study of a series of specimens collected at the same time 
and place, having similar color characters, and an identical 
type of hypopyguim, therefore presumably one species, shows 
that the venation of the wings in this genus is subject to some 
variation, for which allowance must be made in identification. 
The length of the fork of the media is particularly variable. 
In one wing of one of the type specimens of D. fusca Lw. the 
petiole and the fork are nearly subequal in length while in the 
other wing of this specimen and in both wings of the second 
specimen the petiole is noticeably longer than the anterior 
branch of the fork. In D. cornuta described below, a species 
having a very characteristically formed clasper, the variation 
in the proportions is even greater. 
Key to species of Dixa. 
a. Costal half of the wing distinctly smoky; a dark spot at 
the apex of Cu 2; proboscis and scutellum yellow; knob 
of halteres black. D. C marginata Lw. 
aa. Costal part of the wing not distinctly differentiated in color, 
b. Tips of the hind tibise noticeably enlarged, deep black, 
sharply contrasting with the remainder of the member; 
wing veins with clouded margins; proboscis black; hal- 
teres yellowish; scutellum fuscous testaceous; terminal 
clasper segment tapering, mesal process of the basal seg- 
ment simple, elongate. (fig. 2)Me., Mass., N.Y, clavata Lw. 
