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1897 | NORTH AMERICAN SPECIES OF AMBLYSTEGIUM 239 
and adding A. sazatile and A. juratzkanum. In the second 
edition (1876) three new species are added, A. porphyrrhisum 
Lindb., A. leptophyllum Sch., and A. hausmani De Not.; while 
A. saxatile becomes A. hygrophilum. In both editions of this 
work the genus is divided into two subgenera, Amblystegium 
and Leptodictyum. De Notaris in Epilogo della Briologia Italiana 
(1869) recognizes the genus Amblystegium, but makes it include 
many Hypna of the Bry. Eur. Milde in Bryologia Silesiaca 
(1869) adopts in all essential features Schimper’s conception. 
of the genus, but adds Aypnum filicinum Auct. and H. fallax 
Brid. Du Buysson in Essai analytique du genre Amblystegium 
(1883) follows Schimper for generic limits, but reduces several 
Species to varieties. Renauld and Cardot in Musci America 
Septentrionalis (1893) adopt Schimper’s limits for the genus. 
Husnot in Muscologia Gallica (1894) does so with Milde’s modi- 
fications. Dixon and Jameson in Zhe Student's Handbook of 
British Mosses (1896) follow Husnot in large part, but exclude 
A. riparium, which they refer to Campylium. Braithwaite in 
British Moss Flora adopts the limits assigned the genus by D 
Notaris. 
Sullivant in The Mosses and Hepatics of the United States 
(1856) recognizes Amblystegium as a subgenus under Hypnum, 
adopting in general Schimper’s limits, but including Aypnum 
polygamum. In Icones Muscorum (1864) Amblystegium is still 
considered a subgenus of Hypnum. In Lesquereux and James’ 
Mosses of North America the arrangement of Sullivant is followed, 
with the exception of H. polygamum, which is placed under the 
subgenus Campylium. Austin in Musci Appalachiant (1870) fol- 
lows Schimper, but reduces many species of the latter and other 
authors to the rank of varieties. Macoun and Kindberg in 
Catalogue of Canadian Plants \ikewise follow Schimper. 
GENERIC LIMITS. 
To me the generic limits established by Schimper appear to 
be the most natural ones. As thus defined, the genus includes 
at least two species, A. riparium and A. vacillans, whose leat 
4 
