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being more crowded, more closely imbricated, oval at base, then lanceolate, 

 and more shortly acuminate, more obtuse at the apex, with cells very flexu- 

 ous with thicker cell walls. This species, which was collected in 1867 by Mr. 

 W. H. Dall in Alaska, not far from the Yukon river, is described and figured 

 in the Memoire, which the Messrs. Cardot and Theriot are publishing on 

 the Mosses of Alaska, collected on the last expedition of Dr. Trelease. 



H. TuNDR/E Arnell in S. O. Lindberg at Arnell's Musci Asiae borealis, 

 is reported from several localities of the region of the Yenisei river in Siberia. 

 The specimen from Verschiniskoje which Dr. Arnell has communicated to 

 me, has the appearance of a Harpidium with pinnately branched stem and 

 the leaves more or less homotropous (especially the branch leaves), obtusely- 

 acuminate, with the apex often inflexed, and margin more or less denticu- 

 late, especially above the base. The inflorescence is dioicous. 



Hypnum Bakeri n. sp. Tufts very lax, pale-green, below reddish or 

 discolored. Stem slender, without radicles, 8-10 cm. long, prostrate, spar- 

 ingly branched. Leaves distinct, spreading in all directions; thecomal ones 

 ovate or oblong-elliptical, rolled up into an oblong, subacute bud, quite 

 suddenly short acuminate, more rarely subapiculate, obtuse at the top, fre- 

 quently subcucullate by the inflexed apex, more rarely quite long acumin- 

 ate upward, at the base more or less contracted, indistinctly decurrent, occa- 

 sionally plicate, very entire, 1.5-2 mm. long. Costa at the weak base 0.041 

 mm. wide, extending through three-fourths of the leaf, sometimes shorter, 

 rather slender, dissolved below the middle, or else bifurcate. Leaf areola- 

 tion pale, rather loose. Cells from middle of leaf linear-hexagonal, eight 

 times as long as wide, or on smaller leaves six times as long as wide; apical 

 cells shorter, subrhombic; alar cells quite numerous, a little larger, slightly 

 dilated, quadrate, not forming auricles. 



Type locality: Deer Lake, Polk Co., Wisconsin, U. S. A., in a sphag- 

 mum swamp. Coll. C. F. Baker, Nov., 1897. 



This plant has a vague resemblance in appearance to the slender depau- 

 perate forms of Hypnum cordifoliuni. It differs from them by the form of 

 the leaves, which are above narrowed into an obtuse point usually bent in- 

 ward, are not cordate at base, and are hardly decurrent; by the cells of the 

 leaves being often colored, numerous, not or hardly dilated, plane, not form- 

 ing distinct auricles. H. Bakeri approaches H. cordifoliitm, from which it 

 differs by the form of leaf apex, by the leaf base, which is not cordate, and 

 by the closer areolation. 



It has .so far not been possible for me to examine H. brunneo/uscuin, C. 

 Miill., from the peninsula of Tschuctschen in Bering Sea, which, judging 

 from the description of the author (Bot. Centralblatt., 1883,) might be a 

 Pseudocaliergon. 



Finally, this subgenus is established to receive certain species as yet not 

 numerous, but rare, and little represented in herbaria. They are found in 

 boreal or subboreal regions. And it is reasonable to expect that further 

 researches in the vast and incompletely explored regions of northern Asia 

 and America will result in the discovery of other species of this group. 



