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A NEW BRACHYTHECIUM. 
Brachythecium rivulare B. & S. var. tenue n. var. 
A. J. Grout. 
European and Northeastern American forms of B. rivulare , almost 
without exception, have the stem leaves obtuse to obtusely acute, neve r 
slenderly acuminate, but Northwestern American forms seems to, have a 
tendency to vary in the direction of acute to slenderly acuminate stem leaves. 
B. Nelsoni Grout is the extreme limit of this tendency that has thus far come 
under my observation. B. rivulare laxum Grout is another illustration of 
this tendency, and Prof. John M. Holzinger has discovered a third very inter- 
esting form in Lamoille Cave, Minnesota, to which I desire to give the name 
of B. rivulare tenue. 
Prof. Holzinger’s specimens were collected August 23, 1894, and have 
been sent out as “ No. 7, Hypnum.” Specimens have been in my hands for 
some years and the plant has been examined by M. Cardot, but neither of us 
has felt sure of its proper place. Recently, however, I have compared it with 
some specimens of undoubted B . rivulare from Tuckerman’s Ravine, Mt. 
Washington, collected by myself in 1898, and find that the two can scarcely 
be distinguished except by the acuminate stem leaves of the Minnesota plant 
which is briefly characterized as follows: plants prostrate or ascending, 
irregularly branched, slender, very light glossy yellow, lower leaves distant 
and often spreading, the upper closely imbricated, giving the upper portions 
of the plant the appearance of forms of B. oxycladon. Microscopical struc- 
ture like that of slender B. rivulare , except that the stem leaves are acum- 
inate with a rather short slender point. No antheridia, archegonia or 
sporophytes found. 
Type in herbarium A. J. Grout. Co-types will be issued as No. 200 of 
my North American Musci Pleurocarpi. 
MUSCI BORAELI-AMERICANI. 
Fascicle 1. by Prof. J. M« Holzinger. 
A. J. Grout. 
Every student of North American mosses will welcome Prof. Holzinger’s 
Musci Acrocarpi Boreali-Americani as a much needed addition to the knowl- 
edge of our acrocarpous mosses. Mrs. Britton formerly planned something 
of the sort but pressure of other work has caused her to give up the plan. 
The first fascicle of Prof. Holzinger’s mosses are nearly all his own col- 
lecting, and came from an interesting section of the country. There are 
twenty-five numbers in the fascicle and all are abundant in material and 
neatly put up. As the labels do not give the name of the person determin- 
ing the specimens, except in one or two cases, we presume that Prof. HoL 
zinger is responsible for most of the naming, and the determination seem to 
have been made with a care that merits one’s confidence. As Prof. Holzin- 
ger puts up but twenty-five sets those who intend to subscribe should do so at 
once or it will be too late. 
