Potamogeton.] POTAMOOETOWACEiE. 313 



1. In a large lake between Castle G-regory and tlie sea, 

 plentifully; Z>. M — 12. There is a specimen of this species 

 among the plants collected by D. M. many years ago 

 in Antrim. It was probably gathered in Lough Neagh. 

 (Seemann's Journal of Botany, ii., p. 325.) 



10. "P. perfoliatus (Linn.) — Perfoliate Pmd-weed. 

 Districts 1 2 -. 4 5 6 - 8 9 10 11 12 

 Lat 51°-56°. Throughout Ireland. 

 Type in Great Britain, British. 



Ditches, rivers, lakes, &c. ; frequent. Fl. July. 



11. P. crispus (Linn.) — Curled Fond-weed. 

 Districts 123456789 10 -12 

 Lat. 51°-56°- Throughout Ireland. 

 Type in Great Britain, British, inclining to British. 



Lakes, rivers, ditches, and canals ; common. Fl. June, 

 July. 



12. P. zosterifolius (Schum.) — Gtrass-wrach Pond-weed. 

 P. pusillus var. Bentham. 



District ____-____-- 12 

 Lat. 54°-55°. North-east of Ireland — Down only. 

 Type in Great Britain, English. 



Pools and ditches ; very rare. Fl. June, July. 



12. In a pool to the right of the road from Newtonards to 

 Bangor, Down ! Mr. D. Orr. Mr. S. A. Stewart has 

 kindly sent us a specimen of the supposed P. zosterifolius 

 found at Saintfield, which proves to be P. pitsUlus. 



13. P. gramineus (Linn.)^— (rros^y Pond-weed. 

 P. ohtusifolius (Mert. et Koch). P. pusillus var. Bentham. 

 Districts 1 2------- 10 11 12 



Lat. 51°-56°. South and North of Ireland. 



Type in Great Britain, English, inclining to British. 



Ponds, ditches, and bog-drains ; local and rare. Fl. June, 

 July. 



1. Abundant on Ballyphehane bog, near Cork ; /. C. — 

 2. On the east side of East grove, Great Island; in a 



