210 NAIAD ACEiE. 



812. P. densus, L. 



Native; in ditches and streams, common. VI. VII. 



RUPPIA, Linn. 



813. R. rostellata, Koch. 



Native. 



G. In a brackish pool near the Avon below Shire- 

 hampton. V. VIII. 



ZANNICHELLIA, Linn. 



814. Z. palustris, L. 



Native ; in stagnant water, rather common. 



G. Abundant in Avonmouth Marshes. Filton Meads. 



Horfield. 

 S. Pools at Bedmiiister and at Whitchurch. Stockwood. 



Congresbury. Portishead. Yatton. V. — VIII. 



NAIADACE.E. 

 ZOSTER A, Linn. 



815. Z. nana, nntii. 



Native ; in the muddy estuaries. 



816. Z. marina, L. 



Native; on the coast of N. Somerset. 



