(Buchan.) North shore of Lake Superior. (Agassiz.) Lake Mistassini, N.E.T. (J. M. Macoun.) Fort Carleton, Saskatchewan River. (Macoun.) Cumberland House to York Factory, on Hudson Bay. (Hooker, Fl.)

Var. Niagarensis, Gray.

P. Niagarensis, Tuckerman, Amer. Journ. Sci. (2, Ser.) VII., 354.

Rapids above Niagara Falls. (Burgess.) Niagara River, near the brink of the Hog's Back, growing plentifully with Udora; and elsewhere in the river. (Tuckerman.)

(2445.) P. pusillus, Linn.; Gray, Man. Ed. V., 488.

Rather common in ditches, and slow streams. In ditches at Halifax, N.S. (Macoun.) Little Rocher, N.B. (Fowler, Cat.) Vicinity of Ottawa. (Fletcher, Fl Ott.) Common in streams inland, from Pres-cott, Ont. (Billings.) Grand Vallée, Gaspé coast, Q.; in flowing water at Hull, Q.; in the River Trent, at Trenton, and abundant in still waters and ditches throughout central Ontario. (Macoun.) Cockburn Island, Georgian Bay. (J. Bell.) Jones Falls, Rideau River. (Mill-man.) Little Saskatchewan, near Rapid City, and not uncommon in pools in the prairie region. (Macoun.) Lake of the Woods. (Burgess.) Lake Mistassini, N. E. T. (J. M. Macoun.) Specimens referred here were collected at Fort McLeod, B.C., lat. 55°. (Macoun.)

Var. vulgaris, Fries.; Gray, Man. Ed. V., 489.

This is a longer and more branching form, with generally cylindrical and interrupted spikes. Madeline River, Gaspé, Q.; Gull River, Victoria Co.; in deep water, Trent River, Seymour, Northumberland Co., Ont.; Shawnigan Lake, Vancouver Island. (Macoun.) The commonest form at Ottawa. (Fletcher, Fl. Ott.)

Var. panormitanus, Biv.

Rideau Canal, near Ottawa. (Fletcher, Fl. Ott.)

Mr. Morong writes of this variety: "I have carefully compared these (Mr. Fletcher's specimens) with the plant sent me as P. pusillus, L., var. panormitanus, Biv., and can see no essential difference. In my specimens the (submerged) leaves are shorter, they are not ruddy at all, and none revolute. The description of the variety, however, corresponds "leaves longer," (than the type) flaccid, the upper flowering ones opposite and spatulate, the whole surface of the leaf with a pretty chain-like areolation." I am sure that your plant meets this description, and when compared as to the floating leaves the specimens agree. I should not, however, regard it as a distinct species, since it bears so many of the characteristics of pusillus. The ruddy tinge and revolute leaves may be owing to the season or accidental circumstances.

(2446.) P. mucronatus, Schrader.

P. pusillus, var. major, Fries.; Gray, Man. Ed. V., 489.

P. obtusifolius, Macoun, Cat. No. 1737. Bather uncommon but very likely overlooked. St. Stephen, and Little Bocher, N.B. (Fowler, Cat.) Brackish ponds, Salt Lake, Anti-costi; abundant in a brook, North Hastings, O'nt.; marshes at the mouth of Nipigon River, Lake Superior. (Macoun.) Muskeg Creek, Lake Winnipeg, Man.; and Missinaibi River, Ont. (J. M. Macoun.) Long Lake, and Reed Lake, Assiniboia. (Macoun.) In the Red River at Emerson, Man. (Prof. Fowler.)

(244V.) P. rutilans, Wolfgang.

In marshes at Ellis Bay, Anticosti, 1883; also in abundance in marshes at the mouth of the Nipigon River, near Red Rock, Lake Superior, 1884. (Macoun.) On South Twin Island, James Bay, 1887. (J. M. Macoun.) These are the only known localities for this species in America.

(2448.) P. marinus, Linn.; Michx., Fl. I., 102.

P.pectinatus, var. latifolius, Watson; Macoun, Cat. No. 1739, var.

P. pectinatus, var.ß, Hook., Fl. II., 172. Chiefly in brackish marshes on the sea-coast and in the prairie region. Brackish ponds, Salt Lake, Anticosti; Madeline River, Gaspé coast, Q. (Macoun.) Shore of the Gulf of St. Lawrence. (St. Cyr.) Missinaibi Lake and Nelson River. (R. Bell.) Lake Mistassini, N.E.T.; Moose Mountain Creek, Man. (J. M. Macoun.) Common in the larger pools throughout the prairie region. (Macoun.) Ten miles above Spence's Bridge, B.C. (Fletcher.) Further examination will doubtless show that much of the material now referred to P. pectinatus is really this species.

Var. Macounii, Morong. (MS.)

This is a broad-leaved and very distinct form, and cannot be referred to R. marinus, var. Occident alls, although near it, by Rev. T. Morong, who names it as above. Brackish, and salt lakes, prairie region. Old Wives Lakes, and in Crawling Valley, south of the Hand Hills, Alberta. (Macoun.)

(2449.) P. pectinatus, Linn.; Pursh, Fl. I., 121. P. pectinatus, var. a.t Hook., Fl. II., 172.

Widely distributed or confounded with P. marinus. In ponds at

Baddeck, Cape Breton. (Macoun.) Harris Cove, Norton, and Clifton, N.B. (Fowler, Cat.) Along the River St. Lawrence, Q. (St. Cyr.) Common in the vicinity of Ottawa. The typical form. (Fletcher, Fl. Ott.) St. Lawrence River, Conway's Creek, Nation River, and near Prescott, Ont. (Billings.) Jones Falls, Rideau River, Ont. (Millman.) Very common in all the streams in central Ontario, and extending westerly to Victoria Co. (Macoun.) Marsh at Hamilton, Ont. (Logie.) London, Ont. (Burgess.) South Twin Island, James Bay, and Severn River, Keewatin. (J. M. Macoun.) James Bay, near Moose Factory. (Cottar & Dr. Hayden.) Moose Mountain Creek, Man. (J. M. Macoun.) Abundant in the Sydenham River, at Owen Sound, and in all the streams entering Lake Superior; Reed Lake, Assiniboia, and in Red Deer River, Man.; not uncommon in pools and slow flowing streams from Morley westward through the Rocky Mountains to the Columbia; in Somas and Stamp rivers, Alberni, west coast of Vancouver Island. (Macoun.) Crow Nest Pass, Rocky Mountains; Lewes River, lat. 62° N. of British Columbia. (Dawson.) Canada to English River, and from Hudson Bay to alpine lakes in the Rocky Mountains. (Hooker, Fl.) Greenland. (Lange.)

Two very marked forms were found growing together at Black Rapids, Rideau River, near Ottawa, by Mr. Fletcher. Of these forms Mr. Morong writes him: -

(I.) "There is no varietal name for this form, but it is bushy and densely clothed with fine setaceous leaves, and might be called var. tenuissimus, as you suggest.

(II.) This form approaches the "var. (?) latifolius" of Robbins, some of the leaves three nerved."

(2450.) P. Robbinsii, Oakes, Hov. Mag. VII., 128.

Growing usually in deep water and seldom maturing its fruit. Petit-codiac and Hampton; also Tobique Lakes, N.B. (Fowler, Cat.) Little Nictau Lake, N.B. (Hay.) Meech's Lake, Chelsea, Q. (Fletcher, Fl. Ott.) Partridge Lake, Addington Co.; Crow River, Marmora Iron Works; Oak Hill Pond, near Stirling, Hastings Co.; Gull River, near Elliott's Falls, and Gull Lake, near Minden, Victoria Co.; and in the mouth of Nipigon River, Lake Superior. (Macoun.) Oba Lake and Missinaibi River, Ont. (R. Bell.) Lost Lake, near Cedar Hill, and abundant and fruiting in the Somas River at Alberni, on the west coast of Vancouver Island. (Macoun.)