HUNGERFORD: AQUATIC HEMIPTERA. 147 
Shape. Broader than in first instar. 
Structural Peculiarities. The fore tarsal claws which were nearly 
equal in the first instar are now very unequal, one being greatly reduced. 
See plate XVII, figures 8 and 9. “The antenne are now distinctly 2-seg- 
mented and a little more slender, basal segment being about half as long 
as the second.’’—Bueno 
Third Instar. 
Size. Length, 8 to 9 mm.; width 3.7 to 4mm. Other measurements on 
chart. 
Color. Dorsum: General color olivaceous; eyes very dark red. The 
head and thorax mottled with light spots. Meso- and metathorax each 
with two light spots on their fore and rear margins, giving the effect of 
each segment being banded with a dark band. This pattern continues 
along the lateral edge of abdomen producing a similar effect. Besides 
these six light areas on either side, there are two other rows on either side 
consisting of more or less rectangular spots. 
Venter: General color gray with a yellowish tinge. Femora, tro- 
chanters and coxe of all legs nearly colorless. Tibize yellow banded with 
dark, all tibiz with 3 dark bands; tip of fore tarsi marked by dark band; 
tips of other tarsi slightly darker than remaining part. Tips of all 
femora dark banded. The prothorax is crossed on either side by a black 
submarginal band, these bands slightly constricted across the mesothorax 
and fork into two as they cross the metathorax. Base of the abdomen is 
marked on first three segments with some black. The remainder is 
gray with the checkering or banding of the flattened sides of the bug 
as described for the dorsum. 
Structural Peculiarities. The antenne are distinctly 3-segmented, still 
club shaped, and about twice as long as wide. The wing pads are as in 
figure on plate XVII. They extend back on the metathorax so that the 
marginal exposed line of this segment is about one-third the entire line 
of meso- and metathorax together. 
Fourth Instar. 
Size. Length, 11.5 mm.; width, 6.3 mm. Other measurements on 
chart. 
Color. General color as before. A dark band on the margin of vertex 
and a submarginal band on prothorax. . 
_ Shape. About as before. The wing-pads now reach about four-fifths 
of the total marginal length of the meso- and metathorax taken together. 
‘See plate XVII. The antenne are developing two lateral processes in 
this stage. 
Fifth Instar. 
Size. Length, 16 mm.; width, 8.5 mm. to 9 mm. Other measurements 
below. 
Color. Deeper than in previous instars. Wing-pads greyish green; 
abdomen yellowish green with the barring effect along lateral margins. 
