THE GENERA OF MOSSES. 
459 
Brewerianum, and in the " Species Muscorum," the addi- 
tional ones of S. ovatum and serratum ; several of the 
above, however, we consider as mere varieties. Schw^e- 
GRICHEN, in his first Supplement, enumerates in the whole 
fifteen species ; of which, however, we regard gracile 
and S> ovatum as varieties of S. sphcericum, and S. Breweru 
anum as a variety of S. mnioides. In his second Supple- 
ment, he has described S. melanocaulo7i, which is, in our 
opinion, merely a dwarf variety of aS*. luteiim. Sir J. E. 
Smith has still another species, in " English Botany," aS'. 
rugosum of Dickson. We are ignorant whether this be 
really Dickson's plant or not. The authors of " Musco- 
iogia Britannica" state, that, from an examination of Dick- 
son's own specimens, they refer it to *S'. sphoericum. Be all 
this as it may, we have assuredly found the plant so well 
represented in " English Botany," and consider it specifi- 
cally distinct from S. vasculosum^ to which it is nearly 
allied. Dickson, who is the original authority for many 
species taken up by Hedwig and Smith, has described 
another species, about which much doubt has arisen : this 
is S. longicoUum, a plant which has been referred by Doc- 
tors Hooker and Taylor to S. tenue. Brown, on the 
other hand, says that it has never been found in this coun- 
try, " Americae occidentali nec Scotiae indigenum and 
that it is different from S. tenue. 
We have now a few recent works to notice. Out of the 
seven species contained in the " Muscologia Britannica," 
we have referred >S'. FroelicManum to the next genus (JDis^ 
sodon nobis). In Hooker's " Musci Exotici" are two spe- 
cies, S. octohlepharum and S. scabrisetum, the latter of 
which we also refer to Dissodm. Hornschuch, in the 
* Parry's first Voyage, Append, p. ccxcix. 
