296 NEW YORK STATE MUSEUM 
this same lagoon there were a number of plants of the white 
pond lily, Castalia odorata, and as soon as the leaves 
of Nymphaea were raised above the surface of the water - 
the eggs were deposited on the leaves of this plant [pl. 21, 
fig. 1]. In June and early in July the beetles were abundant, ~ 
flitting about on the upper surface of the leaves. As the female 
beetle apparently can not live submerged in water, she has 
adopted the ingenious plan of cutting a hole, round or oval, 
about 4 inch in diameter in the leaf from the upper surface. 
She then inserts her long extensile abdomen [pl.30, figs.4-5] 
through the hole and lays her eggs in a circle on the underside 
[pl.21, fig.4]. Each mass consists of a double row of eggs, 
which are fastened together and to the surface of the leaf 
by an opaque gelatinous substance, which completely covers 
the eggs [pl.21, fig.4]. The eggs are elongate, the sides are 
parallel, and each end is obtusely rounded. The chorion is 
smooth, without surface sculpture and opaque white in color. 
The beetles do not emerge in definite broods, so that eggs in 
all stages of development can usually be collected at almost 
any time during the summer and fall. 
The other species of Donacia differ from palmata in the 
manner and place of laying their eggs. The eggs of cimcti- 
cornis, whose larvae are also found on the roots of 
Nymphaea, are laid in a compact mass on the stems of a sedge 
(pl.21, fig.3], while those of porosicollis are laid in a 
row along the edge of a leaf sheath of the species of sedge 
on which the larvae feed [pl.21, fig.2]. 
The eggs hatch in about 10 days, and the young larvae find 
their way to the bottom of the pond and among the ooze and 
attach themselves to the underground stems of the yellow pond - 
lily. Numerous underground stems of the white pond lily were 
examined, and not a single one was found with the larvae of 
Donacia attached to it, or with any indications of where larvae 
had been feeding on it, though in most cases the stems of the two 
species of plants were intertwined. It is certainly marvelous 
