104 
seen on V. The wings are not large, subcostal vein broad, 
stigma large, radial vein strong, outer two thirds straight, 
directed a little above the tip of the wing, cubital obsolete at 
base, beginning below middle of stigma. Discoidal veins united 
for a short distance at base. Hind wings with but a single 
vein, the discoidals entirelv absent. 
Described from one individual, bred about June 5 from a pupa 
taken May 31 from blue-grass roots in a Lasius nest. 
Among material taken in the fall and winter I find two addi¬ 
tional forms presenting constant differences, and from what I 
know of the forms of related species, I believe them to be the 
sexed individuals, and therefore describe them here. 
Wingless 0 v, parous Female? — Somewhat smaller than the vivip¬ 
arous female, easily recognized by the absence of the peculiar? 
thick, angularly bent, scale-like hairs which constitute the vest! - 
ture of the viviparous female at all ages, these being replaced by 
fine short erect hairs, straight or nearly so, a little longer and 
mbre distinct in younger specimens. Antennae clearly 4-join ted 
in all specimens seen. Spots about and near spiracles usually 
well marked. Genital valves distinct in adult. No trace of 
sensoria other than the usual ones on the last two antennal 
joints. Otherwise as in the viviparous female. 
Length 1.85 mm., breadth 1.25 mm. 
Male? —Small, morp oval, abdomen less expanded, color as 
in the viviparous female, surface clothed with long erect 
hairs, less fine and more conspicuous than in the supposed 
oviparous female. Antennae distinctly 4-jointed, I and II com¬ 
bined about equal to IV; III a little longer. Beak somewhat 
longer than in the preceding fprms. Rows of abdominal spots 
more approximate on each side, hairs of back arranged in rows 
more distinctly than in the young of the form just described. 
Anal plate more projecting, eighth segment more prominent. 
Otherwise not different from the forms already described. Sen¬ 
soria of last two antennal joints as usual. 
Length .8 mm., breadth .41 mm., antenna .28 mm. 
As in related species, a careful search fails to reveal any other 
sensoria, such as those which appear in the sexed individuals of 
Aphis m aidi rad ids. 
The Woolly Grass Root Louse. 
(Rhizohius spicatus, n. sp.) 
(Plate X., Fig. 4.) 
Another grass root louse, belonging to the genus Rhizobius, 
and here described as It. spicatus , has been encountered occa¬ 
sionally on corn in our studies of the insect enemies of that plant. 
It is represented in our collections by six lots of specimens, of 
which one was obtained from a corn field at Urbana April 1, a 
second from grass roots July 20, a third from corn roots at 
