1925 ] 
Notes on the Giant Water Bugs 
91 
Explanation of Plate II. 
Eggs of Belostomatidce . 
Fig. 1. Dorsal view of male of Belostoma flumineum Say bearing 
eggs. 
Fig. 2. Egg cluster of Lethocerus americanus Leidy a little en- 
larged. Note the hatching bug not yet out of its post- 
natal molt and the one that has completely emerged. 
There were 119 eggs in this cluster, arranged roughly in 
6 rows. Each egg measured 4.5 mm. long and 2.25 mm. 
in diameter. The eggs are gray with the free or cephalic 
end blotched with brown, more especially on the exposed 
side of the egg which is on the ventral side of the embryo 
as it emerges. The micropylar area is elongate, light in 
color and surrounded by a brown band. Pale streaks 
radiate from this area arranging the irregular brown 
spots in more or less definite rows. Compare the 
markings of these eggs with that of the one on the right. 
Fig. 3. Hatching egg of Benacus griseus Say : (a) The micropylar 
area, (b) Indicates the space on the head between the 
eyes that pulsates sharply and at irregular intervals. 
Appears to have something to do with the inflation of 
the bubble which lifts the egg cap. (c) The eye. (d) 
The thin transparent membrane that confines the bubble, 
(e) The space not yet filled by the advancing embryo. 
Soon the bug occupies this space and disrupts the mem- 
brane (d) which crumples about the egg shell at (f). 
Copied by Miss Kathleen Doering from a pencil sketch 
by the writer. 
