490 NEW YORK STATE MUSEUM 



OS Opening of the spiracle 



p Pleura 



pc Peripheral layer of chitin of the caudal spines 



pdc Paired dorsal cavities 



pe Peritreme 



2)f Prothoracic filaments 



pr Prothorax 



ps Pedal setae 



pst Posterior sternal setae 



j^t Posterior tergal setae 



pi^c Paired ventral cavities 



px Proximal setae of the labrum 



r Denuded roots 



ICG Rectum 



s Spiracle 



sn Sensory spots 



ss Supraspiracular setae 



St Sternal setae 



t Tracheal taenidia 



tr Trachea 



ttr Transverse tracheal ti'unk 



V Venter 



re Ventral cavity 



vh Vacuolated hypodermal cells 



vv Ventral border paired ventral cavities 



w Cuticular wedge paired ventral cavities 



X Leaf stalks 



V Scars of shed leaf stalks 

 s Larvae 



PLATE 20 



View near the outlet of the Ren wick lagoon, looking southeast. 

 Photo by J. H. Comstock 



PLATE 31 



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 23 



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 J. G. 

 Needham 



a Summit of the plant with beetle on the leaf, b Roots as withdrawn 

 from the water, showing cocoons of Donacia emarginata near 

 the base of the leaves 



