( 4 ) 
antennal plates wide, truncate at apex, apical teeth short ; epistoma rounded 
in front, twice as wide as long ; third maxillipedes hairy on inner sides, hands 
short, smooth above, serrate on inner margin, fingers short, straight, rib- 
bed and punctate above, contiguous margins tuberculate, outer one hairy ; 
third and fourth joints of third thoracic legs hooked ; first abdominal legs 
short, truncate, enlarged towards apex, apical part recurved, then ending 
in three obtuse points turning outward, leaving a wide groove passing up on 
outer side behind teeth. The female has ventral ring flat, with posterior 
margin slightly elevated. Lake Michigan washed up during a violent 
storm.” ( W. T. Bundy.') 
G. troglodytes , Lee. This species I have not yet taken. It is men- 
tioned here on the authority of Dr. Hagen. 
G. virilis , Hagen. A few specimens have been collected at Normal, 
Cairo and Pekin, Ills., all young or of the second form except one male 
from Normal, which belongs to Hagen’s variety A. The thorax is, how- 
ever, broader and smoother, and the areola wider than in the typical form, 
which has been received from Rock river, Wis. 
G. wisconsinensis, Bundy. u Male. Rostrum wide, narrower in front, 
straight, nearly plane above, foveolate at base, anterior teeth small, acumen 
short, acute ; cephalo-thorax cylindrical, punctate, anterior margin not an- 
gulated, lateral tooth obtuse ; dorsal area rather narrow, indistinctly defined ; 
antennal plates longer than rostrum, greatest width in apical half ; antennae 
slender, reaching to middle of abdomen; epistoma as wide as long, truncate 
in front ; maxillipedes hairy on inner side and below at base ; third joint of 
third legs hooked ; first abdominal legs long, bifid, nearly straight, exterior 
part longer, tips slightly recurved ; tips of interior parts recurved, acute, 
swollen near apex. Normal, 111., and Racine, Wis..” ( W. T. Bundy.) 
'C. placidus , Hagen. “ Quincy, 111.,” (Hagen.) I have not seen this 
species. 
G. projpinquus , Gir. Not common. Taken at Normal, Pekin and 
Freeport. 
C. immunis , Hagen. This is the commonest species of central Illi- 
nois. It is especially frequent in the muddy ponds of the prairies, whence 
it may be drawn by the hundred with a small seine. 
The general form of the rostrum of the young is the same as that of 
the adult ; but more or less evident ante-apical teeth are present. The 
abdominal legs of the second form of the male are much thicker at the tip. 
In the first form the branches are slender and distinct throughout the distal 
half of their length, the outer branch is compressed at tip, and the inner 
depressed and widened a little, and channeled on the anterior surface. In 
the second form both branches are equally thick and strong, neither is com- 
pressed or channeled, and the two do not separate except at their tips after 
making the backward turn. The sudden thickening of the leg at its posterior 
middle is much less evident in the second form. 
About one-fourth or one-half the specimens taken from stagnant 
ponds in midsummer are more or less completely covered above by the eggs 
of a species of Corixa , — probably G. alternata , Bay, since this is much the 
