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POTAMOGETON. 385 
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Jolius is reported by Robert Teesdale from a rivulet at Hoving- 
ham, but has not been seen recently. 
Potamogeton crispus L. British type. Native. Area 
general. Range o-250. Common in the ponds and streams 
of the low country, ascending to Semerwater. 
Potamogeton perfoliatus L. British type. Native. 
Area 876.32. Range o-roo: Like the preceding, but less 
frequent, and not ascending into the dales. 
Potamogeton lucens L. English type. Native. Area 
8.321. Rangeo-rso0. In apondat St. Trinian’s ; James Ward. 
Abundant in the Foss at York and in the lower part of the 
Derwent; also more sparingly in Gormire and Scarborough 
Mere. The Gormire plant is erroneously given as prelongus in 
Suppl. Fl. Yorksh. Var. acwminatus with the type in Scar- 
borough Mere; J. Wheldon. 
Potamogeton heterophyllus Schreb. British type. Na- 
tive. Area8.32 1. Range o-300. In the west on Downholme 
Moor ; James Ward ; and frequent about Bedale ; Z. Simpson. 
Plentiful in Gormire, and in the Foss reservoirs below Years- 
ley, and lower down the river about York. 
Potamogeton rufescens Schrad. British type. Native. 
Area 87.3, Range o-200. Ponds at St. Timian /ames 
Ward. In Yore district in a bog in Shand’s pasture, Car- 
perby; and in streams on Thornton Rust Moor; J. Percival. 
In the Howardian tract in Bulmer fields near Castle Howard ; 
Hebblethwaite. Pond near Scarborough ; W. Bean! Abundant 
in Newtondale beck from the upper part of the dale as far down 
as Levisham. 
Potamogeton natans L. British type. Native. Area 
general. Range o-r50. Common in ponds in the low country, 
ascending to Wensley and Aske. 
Potamogeton oblongus Viv. British type. Native. 
Area 9 876543 2,. Rangeo-550, Common in peaty pools, 
Bot. Trans, Y.N.U.., Vol. 3. Z 
