112 THE BOTANICAL EXCHANGE CLUB OF THE BRITISH ISLES. 
stipules blunter, the submerged leaves having lacinice , the fruits smaller 
and more rounded. The submerged leaves, especially the young 
ones, are of very thin texture. From all states of polygonifolius it 
differs at once by the thick peduncles , larger flowers, and larger fruit. 
The forms it is liable to be mistaken for are — Of natans : The var. 
prolixus , of Fr. ( P. serotinus , Schrad.) ; and of polygonifolius, the var. 
pseudo-fluitans , of Syme. The question of the phyllodia of P. natans 
I have not yet been enabled to trace by growing specimens, but in 
specimens of a form of polygonifolius , watched for five years (from 
N. Wales — J. E. Griffith), I find the laminae to drop off, leaving the 
petioles, which become nearly white, but in this state are persistent to 
October and November. The leaves of this form assume a very 
natans- like look, much like the specimens from “Fleet Pond, N. Hants,” 
in Mr. H. C. Watson’s herbarium at Kew. It is this form of polygoni- 
folius that is often named natans ! When in fruit, however, there is 
no difficulty. The distribution of P. fluitans, Roth., is not yet worked 
out, the barren specimens in various herbaria being extremely difficult 
to separate from some others. My herbarium contains the true plant 
from Prussia, Italy, Denmark, France, Siberia, Algeria, Socotra, and 
the Argentine Republic. I have seen specimens in various herbaria 
from Switzerland, Austria, Portugal (Herb. Berlin), Arabia, Persia, 
Abyssinia, Morocco, and other countries. I have had living specimens 
under my eye for the last four years, kindly sent by M. J. Lloyd, of 
Nantes, and I am inclined (on present knowledge) to agree with those 
Continental authors who separate it from natans and polygonifolius , 
but I should wish to see natans grown by their side before expressing 
a decided opinion ; this I hope to do. While writing this notice, a 
specimen of a Potamogeton comes from Ireland (R. M. Barrington), 
which is not sparganifolius or polygonifolius , and is either the P. natans , 
v. prolixus, or P. fluitans, Roth., but the specimen is too young and 
not sufficient for determination. I hope to obtain it later on. It may 
be the fluitans, var. rivularis , Lange, of which I possess specimens from 
the author. I hope any botanist who visits Ireland this autumn will 
pay special attention to its aquatic plants. 
Potamogeto?i natans, L. (seg.) Canal, near Bath, N. Somerset, V.C. 
6th August, 1884. — W. B. Waterfall, com., A. Bennett. Additional 
record of V. C. 
Potamogeton polygonifolius , Pour., var. b. pseudo-fluitans. Margin of 
Llyn an-afon, S. of Llanfair-fechan, N.E. Carnarvonshire, 29th Sept., 
1884. — Charles Bailey. Not pseudo-fluitans of Syme; I think it 
must come under natans , and is near to var. prolixus , Koch, 
resembling a specimen I have from Silesia (Herr von Uechtritz), with 
a note “ assentiente cel Nolte.” There is a fine form of polygonifolius 
that occurs in this Lake (August, 1883. — J. E. Griffith and W. W. 
Reeves) with large thin leaves, and stipules highly colored. A plant 
similar in habit to Mr. Bailey’s, but with the leaves and stipules of 
polygonifolius , occurs in Llyn-y-galasr (alt. 1,500 ft.), in Cardiganshire, 
— Mr. E. Straker ! and shows clearly that Mr. Bailey’s plant belongs 
to natans. In a notice of the Student’s Flora, 3 ed., in “ The 
Naturalist,” for October, 1884, the reviewer considers “ polygonifolius, 
Pour., to bear a somewhat similar relation to natans that Zizii does to 
