490 NEW YORK STATE MUSEUM 
os Opening of the spiracle 
p Pleura 
pe Peripheral layer of chitin of the caudal spines 
pde Paired dorsal cavities 
pe  Peritreme 
pf  Prothoracie filaments 
pr Prothorax 
ps Pedal setae 
pst Posterior sternal setae 
pt Posterior tergal setae 
pve Paired ventral cavities 
pe Proximal setae of the labrum 
Yr Denuded roots 
rec Rectum 
S Spiracle 
sn Sensory spots 
SS Supraspiracular setae 
st Sternal setae 
t Tracheal taenidia 
tr Trachea 
tir ‘Transverse tracheal trunk 
v Venter 
ve Ventral cavity 
vh Vacuolated hypodermal cells 
vv ~=Ventral border paired ventral cavities 
Ww Cuticular wedge paired ventral cavities 
£ Leaf stalks 
y Scars of shed leaf stalks 
z Larvae 
PLATE 20 
View near the outlet of the Renwick lagoon, looking southeast. 
Photo by J. H. Comstock 
PLATE 21 
1 Portion of leaf of Nymphaea advena, showing eggs of 
Donacia palmata. Photo by J. G. Needham 
2 Portion of leaf of a sedge, showing the eggs of Donacia 
porosicollis 
3 Eggs of Donacia cincticornis 
4 A single egg mass of Donacia palmata 
PLATE 22 
Underground stem of Nymphaea advena, showing larvae 
and cocoons of Donacia palmata. Photo by J. O. Martin 
PLATE 23 
Plant of Sparganium androcladium.. Photo by 2. 
Needham 
a@ Summit of the plant with beetle on the leaf. 6 Roots as withdrawn: 
from the water, showing cocoons of Donacia emarginata near 
the base of the leaves 
