40 
the main difference is the width and ‘shape of the leaves, and the 
broad, rounded entire apex. We have seen all of Prof. Macoun’s 
specimens, and tried the following experiment; taking several 
stems from different ‘plants, we divided them into 5-6 sections 
each, and compared the leaves. In all cases we found that the 
upper green leaves at the tips of the branches were longer and 
narrower, more acuminate and more sharply serrate, with the apex 
also serrate and generally cucullate; the lower cells also were 
seldom differentiated, generally paler and oblong, not prosenchy- 
matous. The lower leaves on the same plants were shorter and 
broader, often entire and rounded at apex, the cells denser and 
darker, and often yellow with traces of prosenchymatous cells. 
We have not been able to find that any of the characters are 
constantly associated together, so that we cannot maintain S. Vev7 
as a species, even if the name had priority over the var. igrescens ; 
but there seems to be sufficient reason in maintaining the latter as 
a variety, as we have shown from the descriptions of Drummond's 
specimens and Macoun’s collections. 
We found one of Macoun’s specimens of “« S. Nevii” agreed 
with the specimens from Yale labelled var.-virescens (Bull. Torr. 
Bot. Club 16: 93, 1889), having the upper leaves of that brilliant 
emerald green color which is so striking in these specimens. Oa 
the younger and smaller plants the leaves are green. Large, 
coarse, old plants, with ragged leaves, are almost black. 
ScouLerta Mue.tert Kindb.; Macoun’s Catalogue, 6: 62 (1892). 
Macoun’s Canadian mosses, No. 558. 
The description calls for different specimens from those of No. 
558, which we have received from Prof. Macoun. Those sent us 
are undoubtedly referable to S. aquatica, with which they agree in 
every way. The poe reads the median basal cells “ linear, 
porose and aeroUs,, the apex entire rounded, and the margin 
“pale orange.” In our specimens the basal cells are rectangular, 
with a few very faint traces on some of the leaves of the yellow 
prosenchymatous cells referred to in the description. The apex 
is as often serrate as entire, and the marginal cells are green, in 
6-7 rows, and though larger and more distinct than the inner 
ones, are = not “pale orange.” 
