Ruppia.] POTAMOGETONACE^. 315 



16. P. filiformis (Nolte.) — Slender Pond-weed, 

 P. marinus (Fries.) Gren. et Godr. P. pectinaMs var. Bentham. 

 District ______8---- 



Lat. 53°-54:°- "West of Ireland— Mayo only. 

 Type in Great Britain [Scottish]. 



Lakes in mountainous districts; very rare. Fl. June, 

 July. 



8. Abundant in shallow water in Lough Cullin, at the 

 outlet of the river which falls into the Moy ; A. G. M, 

 Strictly speaking this locality extends to both districts 8 

 and 9. 



17. P. densus (Linn.) — Opposite-leaved Pond-weed. 

 Districts 123456------ 



Lat. 51°-54°. Southern half of Ireland. 

 Type in Great Britain, English. 



Kivers, ditches, canals ; very local and rare. Fl. June, 

 July. 



1. Killamey ; C G. B. — 2. In the river Suir, near Clonmel ; 

 D. M. Pond at Tubberaheena, Tipperary ; Miss A. Taylor. — 

 3. In the county Kilkenny, near Waterford ; /. C. — 4. In the 

 Slaney, near Enniscorthy ; Mr. J. Morrison. — 5. In the canal 

 at Portobello, Dublin ; D. M. (probably brought by the turf- 

 boats). — 6. About Limerick, not unfrequent (Prof. Harvey) ; 

 Flor. Hib. ; and probably elsewhere along the course of the 

 Shannon. 



Ohs. — P. aoutifolius is represented in Dr. Mackay's Her- 

 barium by a specimen bearing lanceolate submerged leaves, 

 probably belonging to P. polygonifoUus. 



RUPPIA Linn. 

 1. E. maritima (Linn.) — tassel Pond-weed. 



Districts 12-456---- 11 12 

 Lat. 51°-56°. Coasts of all Ireland. 

 Type in Great Britain. 



Brackish pools and ditches; not unfrequent. Fl. July 

 August. 



Var. ,3 rostdlata (Jt. rostellata, Koch.) 



