HUNGERFORD: AQUATIC HEMIPTERA. 209 
mass above the net. After prodding among this material and getting 
stung by Naucorids until a retreat was necessary, we would take the 
material to the bank and work it over, taking dozens on the way.” 
The “sting” of this insect is indeed painful for a time, and it leaves a 
stinging, itching, burning sensation for some time, as the writer has 
found. 
DESCRIPTION OF STAGES. 
Pelocoris femorata. 
The following is taken from Bueno, 1903. The writer has reared 
P. carolinensis in part, but has never had the time to describe the ma- 
terial: 
The Egg. 
Size. “Length, 1.4 mm.; width, .6 mm.; altitude, .7 mm. 
Shape. “‘From above, imperfectly oval; from the side somewhat flat- 
tened above, with a gradual rise toward the middle. The cephalic end is 
more rounded than the caudal, descending to the line of attachment 
with a shorter curve. This curve is somewhat depressed at the ex- 
tremity of the ovum, from which depression arises the micropylar boss. 
The form changes during incubation and just previous to emergence 
the ovum is larger and. rounder than when first deposited.” 
Color. ‘Translucent, pearly white when deposited, growing darker 
as development progresses. The surface is minutely punctulated in 
lines, punctures set close together, giving the appearance of meandering 
striations. As the time for emergence approaches, the character of the 
markings changes. The chorion is still punctulated, but at the same 
time engraved in distinct hexagons, produced by the punctulations.” 
First Instar. 
Size. “Length, 2.5 mm.; width, 1.5 mm. 
“Immediately after emerging from the ovum, the nymph is trans- 
parent, white and colorless, except that each abdominal segment has a 
broad, dark, luteous band at the connexivum. Also, the eyes are red 
and well-marked. The tarsal claws of the second and third pairs of 
pedes are dark and noticeable. The single claws of the first pair are 
colorless and transparent. The short rostrum is transparent pale 
luteous, darker at the tip. A seta issues from the posterior angle of 
each abdominal segment, at the connexivum, on the dorsal surface. 
About eight hours after emergence the insect is much darker in color. 
“In shape the young Pelocoris resembles nothing so much as the 
suctorial midnight prowler, at a superficial glance. Carefully examined, 
however, it is seen to resemble closely the adult in shape, allowing for 
the difference in size and absence of wing's. 
“When recently hatched its abdominal air coating is absent, and the 
young insect finds it difficult to reach the surface, which it succeeds in 
doing only by vigorous swimming. If it relaxes its efforts, it immedi- 
ately sinks to the bottom. Pelocoris swims back down when in this 
condition. 
“When still uncolored, the dorsal vessel can be plainly seen pulsating 
and the oily globules of the unabsorbed yolk moving in the abdominal 
cavity.” 
Second Instar. 
Size. “Length, 3.25 mm.; width, .2 mm. 
“The appearance after the molt is practically the same as after emer- 
gence from the ovum, except that there is a dark, somewhat triangular- 
shaped blotch extending from the caudad margin of the thorax to the 
fourth abdominal segment, apparently produced by the abdominal con- 
14—Sci. Bul.—1669 
