MEMOIRS 
OF THE 
TORREY BOTANICAL CLUB. 
Vol. VI. No. 2. 
A Revision of the North American lsotheciaceae and Brachythecia. 
By ABEL JOEL GROUT. 
The work on the Isotheciaceae and Brachytheciaceae was un- 
dertaken with the purpose of correlating and bringing up to date 
the later work on the American plants of this group which has 
been done largely by foreigners and has been published in various 
scientific publications, some of which are difficult of access. Barnes 
and Heald’s new Keys to the Genera and Species, it is true, con- 
tain all these collected descriptions, but it has been felt by every 
student of American bryology that much of the recent work, es- 
pecially that of Nils Conrad Kindberg, was, to say the least, of un- 
certain value. The sentiments expressed by Dr. Barnes concern- 
ing this matter in the preface to the second edition of his Keys, are 
heartily approved by every American bryologist. A very large 
proportion of the new species in this group has been founded on 
insufficient and incomplete material and the descriptions of perfect 
specimens even have often been entirely inadequate for the deter- 
mination of the species. 
My thanks are especially due to Professor John Macoun, Dr. 
William Mitten and M. Jules Cardot for notesand specimens. By 
Professor Macoun’s kindness I have been able to examine type 
collections of most of Kindberg’s new species. Professor Macoun 
assures me that the specimens of Brachythecium harpidiodes, B. 
lamprochryseum, B. gemmascens, B. rutabuliforme, B. pseudo-colli- 
num, B. nanopes, B. platycladum and B. mirabundum “ are abso- 
lutely identical with those named by Kindberg.” 
