490 NEW YORK STATE MUSEUM 



OS Oiit'iiing of the spiracle 



p Pleui'a 



pc Peripberal layer of chitin of the caudal spines 



pdc Paired dorsal cavities 



pe Per itr erne 



pf Prothoracic filaments 



pr Prothorax 



ps Pedal setae 



pst Posterior sternal setae 



pt Posterior tergal setae 



pvc Paired ventral cavities 



px Proximal setae of the labrum 



r Denuded roots 



reo Rectum 



s Spiracle 



sn Sensory spots 



ss Supraspiracular setae 



St Sternal setae 



t Tracheal taenidia * 



tr Trachea I 



ttr Transverse tracheal trunk 



V Venter 



ve Ventral cavity 



vh Vacuolated hypodermal cells 



vv Ventral border paired ventral cavities 



IV Cuticular wedge paired venti*al cavities 



X Leaf stalks 



y Scars of shed leaf stalks 



z Larvae 



PLATE 20 



View near tlie outlet of the Renwick lagoon, looking southeast. 

 Photo by J. H. C'omstock 



PLATE 21 



1 Portion of leaf of Nymphaea advena, showing eggs of 

 D o n a c i a pal m a t a . Photo by J. G. Needham 



2 Portion of loaf of a sedge, showing the eggs of Donacia 

 poroslcollis 



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 



i 



1 



Plant of Sparganium androcladlum. Photo by J. G. 

 Needham 



a Summit of the plant witli beetle on the leaf. 6 Roots as withdrawn 

 from the water, showing cocoons of Donacia emarginata near | 



the base of the leaves 



