(153.) P. cavifolia, Ehrh.; Lesq. & James, Mosses of N. America, 101.

Gmynostomum ovatum, Drumm. Musc. Bor. - Am., Nos. 17 and 18.

Mountain prairies and plains of the Saskatchewan (17). Rocky Mountains; very rare (18.) (Drummond.) On dry earth in crevices of rocks at Lytton, B.C., 1889. (Macoun.)

(154.) P. truncata, Fuern.; Lesq. & James, Mosses of N. America, 101; Canadian Musci, No. 62, in part.

On earth in fields, James Terrill's farm, near Wooler, Northumberland Co., Ont. (Macoun.)

(155.) P. intermedia, Fuern.; Braithw. British Moss-Flora, 197.

P. truncata, Canadian Musci, No. 62, in part.

On earth on the Portage between Lesser Slave Lake and Peace River, September 23rd, 1872. (Macoun.)

(156.) P. littoralis, Mitt.; Braithw. British Moss-Flora, 198. P. truncata, Canadian Musci, No. 62, in part. On earth at Yale, B.C., May 17th, 1875. (Macoun.)

(157.) P. Heimii, Fuern.; Lesq. & James, Mosses of N. America, 102.

Gymnostomum Heimii, var. I., var. II., var. III., Drumm. Musc. Bor. - Am., Nos. 13,14 and 15 respectively.

Muddy swamps in the mountains; rare (No. 13); muddy swamps in the mountains (No. 14); bank of Hayes River below York Factory, Hudson Bay (No. 15). (Drummond.) Greenland. (Fl. Gr.)

(158.) P. latifolia, Muell.; Lesq. & James, Mosses of N. America, 103.

Greenland. (Fl. Gr.) On rocks, Mount Alymer, Rocky Mountains, alt. 8,000. (Macoun.)

Var. pilifera, Muell.; Lesq. & James, Mosses of N. America, 104.

Weissia latifolia, Drumm. Musc. Bor. - Am., No. 70.

Summits of the mountains; not uncommon. (Drummond.) On earth near Cache Creek, B.C. (Macoun.)

(159.) P. heimioides, Kindb. (n. sp.)

Nearly allied to P. Heimii but differs in the leaves being shorter, the lower obtuse, the costa sometimes ex current, the capsule longer and narrower, cylindric, the seta golden yellow, and the peristome present but rudimentary.

The allied Pottia riparia, Aust., is described by Lesq. & James as having "a conical mamillate lid, the costa of the leaves vanishing below the apex." These characters do not correspond with the Canadian specimens (No. 719 from Câche Creek, B.C., May 25th, 1875, and Canadian Musci from the Gaspé coast), sent by Prof. Macoun; they probably belong to another new species.

On earth along Cave Avenue, a little above the Bow River Bridge, National Park, Banff, Rocky Mountains, July 4th, 1891. (Macoun.)