AQUATIC INSECTS IN NEW. YORK STATE . 491 
PLATE 24 
Sections of the stem of Sagittaria | 
1 Cross section. 2 Longitudinal section, both showing intercellular 
spaces and arrangement of tissues 
3,4 Hgegs of Donacia porosicollis 
PLATE 25 
Donacia 
Anatomic details of the larvae. Enlarged 
_ , DONACIA CINCTICORNIS 
1 Mandibles. 2 Antennae. 38 Leg. 4 Maxilla. 5 Labium. 6 Labrum 
DONACIA PALMATA 
7 Maxilla. 8 Antenna. 9 Labrum. 10 Hyes. 11 Mandibles. 12 Leg 
DONACIA SUBTILIS 
13 Hye. 14 Leg. 15 Mandibles.. 16 Maxilla. 17 Labrum. 18 Labium. 
19 Antenna 
PLATE 26 
Donacia 
Anatomic details of the larvae. Enlarged 
DONACIA POROSICOLLIS 
1 Mandibles. 2 Maxilla. 3 Labrum. 4 Labium. 5 Leg. 6 Eyes. 
7 Antenna 
DONACIA AEQUALIS 
8 Mandibles. 9 Maxilla. 10 Antenna. 11 Labrum. 12 Leg 
DONACIA EMARGINATA 
13 Labrum. 14 Antenna. 15 Labium. 16 Maxilla. 17 Leg. 18 Man- 
dibles 
PLATE 27 
- Haemonia, Galerucella and Donacia palmata 
Anatomic details of the larvae 
HAEMONIA NIGRICORNIS 
1 Mandibles. 2 Labrum. 3 Labium. 4 Leg. 5 Hyes. 6 Maxilla. 
7 Antenna . 
GALERUCBELLA NYMPHABAB 
8 Mandibles. 9 Labrum. 10 Leg. 11 Labium. 12 Maxilla 
DONACIA PALMATA 
18 Larva just emerged from the egg. 14 Dorsal apodeme. 15 Longi- 
tudinal section of a trachea. 16 Surface section of trachea showing 
taenidia. 17 Lateral view of apex of abdomen of mature larva. 18 Por- 
tion of a stem of Nymphaea advena witha mature larva feed- 
ing with its head and thorax buried in the tissues of the plant. 19 Dorsal 
aspect of the four apical abdominal segments of a mature larva 
PLATE 28 
Donacia palmata 
Anatomie details of the caudal abdominal spiracle. Enlarged 
1 Portion of a stem of Nymphaea advena with a mature larva 
attached to it by its caudal spines, in the act of respiring 
2 Lateral view of a caudal spine and its internal attachment 
3 Apex of a caudal spine still more enlarged 
4 A transection of a caudal spine at the level d-e of figure 2 
5 A transection of a caudal spine at the level f—g of figure 2 
