240 BOTANICAL GAZETTE [ OCTOBER 
structure, considered alone, might place them elsewhere; but 
when account is taken of the sum of their characters, they must be 
referred toAmblystegium. Icannot agree, therefore, with Messrs. 
Dixon and Jameson, who, in their recent admirable Handbook, have 
placed the former in the genus Campylium. Nor can I accept 
the inclusion of Hypnum filicinum and its near relatives in Ambly- 
stegium by Husnot in Muscologia Gallica, in which he is followed 
by Dixon and Jameson. Here again the sum of the characters 
should decide the position of the plant. It appears to me that 
the very general hypnoid facies, the paraphyllia and the inflated 
alar cells, together with leaf cells otherwise not entirely of the 
Amblystegium type, ought to exclude it. 
De Notaris, Mitten, Kindberg, and Braithwaite extend the 
limits of the genus so as to include several other groups of the 
Hypnacez. With these proposals I cannot agree unless we 
are content to go back to the comprehensive idea of the 
genus Hypnum. Should I go as far as these authors propose, I 
can see no reason why I should not include all the Hypnacee. 
The species of Limnobium, for example, are, I think, quite 
as closely related to the plants included by Braithwaite in 
Eu-Amblystegium as are the species of Calliergon, which he 
refers to Amblystegium. Yet the Limnobia are not included. 
DISTRIBUTION. 
I have been able to separate sixteen species. Ten of these 
are found both in Europe and North America. Five others, 
AA. minutissimum, lescurii, compactum, noterophilum, and vacillans, 
are exclusively: North American. The sixteenth, A. adnatum, 
is found in North Americaand Japan. Of these, three, AA. ser- 
pens, varium, and riparium, are found in most parts of the United 
States and southern Canada, the first being less common than 
the others. A. adnatum is widely distributed, though not abun- 
dant, in the southeastern United States. A. compactum may be 
considered northern, though it extends south in the Rocky 
mountains to Colorado; A. sprucei has a similar distribution, 
though not found at as many stations; A. fluviatile, so far as 
