262 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



LEMNACE^. 

 Duck-weed Family. 



81. Lemna polyrrhiza, L. Duckweed ; Duck's Meat. 



TYPHACEiE. 



Cat-tail Family. 



82. Typlia latifolia, L. Common Cat-tail ; Reed-mace. Common. 



83. Typha angustifolia, L. Small Cat-tail ; Narrow-leaved Cat-tail. 



(Europe.) 



84. Sparganium eurycarpum, Eng. Bur-reed. New England and Penn- 



sylvania, northward and westward. 



85. Sparganium simplex, Hudson. New England and northward. 



(Europe.) 



NAIADACE^E. 



Pondweed Family. 



86. Naias flexilis, Eostk. Naiad. Common. (Europe.) 



87. Zannichellia palustris, Micheli. Horned Pondweed. Rather rare. 



(Europe.) 



88. Potamogeton amplifolius, Tuckerman. Pondweed. Not rare. 



89. Potamogeton Claytonii, Tuckerman. Common. 



90. Potamogeton compressus, L. Not common. 



91. Potamogeton crispus, L. Delaware, Pennsylvania, and New Jersey. 



92. Potamogeton gramineus, L. The commonest form. (Europe.) 



93. Potamogeton gramineus, L., var. spathulneformis. 



94. Potamogeton gramineus, L., var. myriophyllus, R. 



95. Potamogeton hybridus, Michx. 



9G. Potamogeton lonchites, Tuckerman. New England to Illinois. 



97. Potamogeton lucens, L. Not common. In the Potomac. 



98. Potamogeton lucens, L., var. minor, Nolte. 



99. Potamogeton lucens, L., var. Conuecticutensis. 



100. Potamogeton natans, L. Common. (Europe.) 



101. Potamogeton Niagarensis, Tuck. Rapids above Niagara Falls. 



102. Potamogeton Oakesianus, Robbins. Not rare in Eastern Massachu- 



setts. 



103. Potamogeton obtusifolius, Mortens & Koch. Very rare. Pennsylva- 



nia and Michigan. 



104. Potamogeton pauciflorus, Pursh. Common. 



105. Potamogeton pectinatus, L. Common. 



10G. Potamogeton perfoliatus, L. Common. 



107. Potamogeton prselongus, Wulfen. East New England and along the 

 Great Lakes to Lake Superior. 



