490 NEW YORK STATE MUSEUM 



OS Oiifiiinj^' of the spiracle 



p Pleura 



pc Peripheral layer of chitiu of the caudal spines 



pdc Paired dorsal cavities 



pe Peritreme 



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 Supra spiracular setae 



St Sternal setae 



t Tracheal taenidia 



tr Trachea 



ttr Transverse tracheal trunk 



V Venter 



vc Ventral cavity 



(7( Vacuolated hypodermal cells 



vc Ventral border paired ventral cavities 



10 Cuticular wedge paired ventral cavities 



X Leaf stalks 



y Scars of shed leaf stalks 



z Larvae 



PLATE 30 



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

 Photo by J. H. Comstock 



PLATE 31 



1 Portion of leaf of Nymphaea ad vena, showing eggs of 

 Dona c la 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 33 



Underground stem of Nymphaea ad vena, showing lai'vae- 

 and cocoons of Donacia palmata. Photo by J. O. Martin 



PLATE 33 



Plant of S p a r g a n i u m a n d r o c 1 a d 1 u m . 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a Summit of the plant with beetle on the leaf, b Roots as withdrawn- 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 e m a r g i n a t a near 

 the base of the leaves 



