22 
Britton’s care, and the hepatics with the algae, under Dr. Howe’s 
care. The ee _ the Mitten Herbarium of mosses anc 
hepatics, an account which was published in the JouRNar 
for February, 1907, has eo necessary a great deal of mount- 
ing, as all his specimens were laid loosely in folders or pinned tc 
sheets and these are gradually being incorporated with collections 
already at the Garden. The American species, including those 
from South America, Central America and the West Indies are 
parison d exchanges which throw light on our knowledge 
before the publication of the volume on mosses of “‘ North Ameri- 
can Flora.” It is increasingly evident that there has been much 
duplication of naming by various European authors and we 
acknowledge our ee to Professor Max Fleischer and 
Dr. Urban of the Royal Botanical Garden and Museum at 
Berlin for numerous comparisons with the aroinals of American 
species named by S. E. Bridel and Karl Miller. We are also 
under lasting obligations to Mr. C. H. Wright at Kew Gardens 
and Mr. Anthony Gepp at the British Museum of Natural 
History at South Kensington for comparisons with valuable col- 
lections preserved at these two institutions. It is expected that 
some adequate acknowledgment will be made when we come to 
distribute the duplicates from the Mitten Herbarium and the large 
number which have accumulated as a residue from our West 
Indian collections. We are also indebted to Messieurs Renauld 
and Cardot for portions of types or authentic specimens of many 
of their Central American and North American species and have 
arranged for an exchange of notes and specimens with Mr. V. F. 
Brotherus, who is enumerating the mosses of the world for Engler 
and Prantl’s Natirlichen Pflanzenfamilien. 
An effort has been made to follow critically all the species 
listed from North America and a card catalogue has been kept 
for this purpose, to which are added corrections in synonymy 
and extensions of range. These cards now record 148 acrocar- 
pous genera with 1,642 species and 98 pleurocarpous genera with 
491 species, and the enumeration is not yet completed 
rom Mr, William R. Maxon, of the National Museum, we 
