NOETHUMBEKLAND AND DURHAM. 265 



5. P. crispus, L. Native. British type. Area C, N, D. 



Range 1. 



Frequent in ditches and slow streams, ascending to the Till at 

 Wooler, in Coquetdale to Rothbury, in Weardale to Stanhope, 

 200 yards. 



6. P. perfoliatus, L. Native. British type. Area C, N, D. 



Range 1. 



Frequent in slow streams, ascending to Crag Lough, 200 yards. 



7. P. lucens, L. Native. English type. Area C, N, D. 



Range 1. 



Plentiful in the Tweed, especially about the Union Bridge (Dr. 

 Johnston). In the Aln and ponds near Alnwick (R. Embleton). 

 In Tynedale in Crag Lake, 200 yards, the lake at Dudley Shiels, 

 the mill-race at Hexham, and Prestwick Carr (F. R !). Ponds 

 near Darlington, and in the Skerne (W. Backhouse. F !). 



8. P. prcBlongus, Wulf. Native. Scottish type. Area C. 



Range 1. 



Mentioned in the Transactions of the Berwick Clnb for 1854 

 as having been gathered in the Tweed near the Union Bridge. 



9. P.heterophyllus^'^ieh. Native. British type. AreaN, D. 



Range 1. 



In Tynedale in Haltwhistle Burn below Walltown (W. H. 

 Brown!). Prestwick Carr (F. R!). Pools near the Wescrow 

 Bum in Waskerley Park (F.). 



10. P. rufescens, Schrad. Native. British type. Area C, N, 

 D. Range 1, 2. 



Ponds on Alnwick ]\Ioor (J. Davidson. F !). Swinhoe Lough, 

 and in the pond below Kyloe Crags (R. Embleton). Crag Lough 

 and Greenley Lough (R !). In the Weel with Ranunculus pel- 

 tahis at an elevation of 500 yards (B.). 



