W ilson, in Bryologia B r it. (1855), arranged them somewhat
as Bridel.
1. Lea ve s obtuse, rounded, or elliptic.
S', cymbifolium, compactum, molluscum, rubellum.
2. L ea ve s acuminate, ovate or ovato-lanceolate.
a. L ea ve s erecto-patent.
S. acutifolium, fmbriatum, cuspidatum, contortum.
aa. Lea ve s squarrose.
S', squarrosum.
S u l l iv an t , in his Mosses o f the United States (1856), forms
four groups, characterized by the relative position o f the cells in
the branch leaves, as seen in transverse section— a valuable
distinction, no doubt, but far too minute and difficult o f observation
to be o f practical utility.
1. Chlorophyllose cells entirely enclosed by the hyaline, and
not reaching either surface o f leaf.
S . cymbifolium, compactum, contortum, Lescurii, tenerum,
humile, cyclophyllum, sedoides.
2. Chlorophyllose cells oval, reaching to both surfaces o f leaf.
S', squarrosum, macrophyllum.
3. Chlorophyllose cells triangular, placed between the hyaline
at the concave or inner surface o f leaf.
S. acutifolium, fmbriatum, tabulare, molle.
4. Chlorophyllose cells triangular, placed between the hyaline
at the convex or outer surface o f leaf.
S . cuspidatum, Torreyanum.
S chimper, in his monograph, divides the species into two
groups— monoicous and dioicous— a plan o f v e ry little practical
help, since it is o f no use with plants in a barren state. T h e same
arrangement is followed in the Synopsis Muse. Europ. ed. i
(1860).
C. H a r tm an, in the eighth edition o f the Scandinavian Flora
(1861), uses the stem leaves for this purpose, thus :— ■
1. A p e x o f cauline le a f broad, strongly and distinctly fimbriate
in its whole margin.
5'. cymbifolium, Angstrbmii, Lindbergii, fmbriatum.
2. A p e x indistinctly fimbriate or lacerate.
6'. rigidum, squarrosum, subsecundum, teres.
3. A p e x with a few distinct teeth, not fimbriate or lacerate.
S. acutifolium, Mulleri.
4. A p e x entire or indistinctly denticulate.
S . molluscum, rubellum, cuspidatum.
This, it will be seen, is readily applicable, but it has the disadvantage
o f bringing together species not otherwise the least allied.
L indb erg, in Ofvers. K . Vet. A k . Forhandl. for 1862, after
separating S . macrophyllum as a genus Lsocladus, arranges the
rest as follows :—
1. Homophylla. Plants glossy, shining; hyaline cells quite
free from spiral fibres.
sericeum, Holleanum.
2. Heterophylla. Plants opake ; hyaline cells furnished with
spiral fibres.
A . S. cuspidata.
6'. cuspidatum, Lindbergii, recurvum, fmbriatum,
acutifolium, teres, squarrosum.
B. S. rigida.
S . rigidum, Mulleri, Angstrbmii.
C. S. subsecunda.
6'. subsecundum, rubellum, tenellum.
D. S. cymbifolia.
.S. cymbifolium.
T he se groups are natural, have several characters in common,
and are also adopted by Russow and Milde, except that they alter
rigida to trnncata, a more appropriate term, since it is applicable
to all three species.
I have also followed this arrangement, but at Professor Lind-
berg’s suggestion have reversed the order, so as to commence with
what we must consider the most highly developed species o f the
genus.
ScHLiEPHACKE, in the paper already referred to, proceeds on
the same plan, but increases the number o f groups to seven, as
follows :—
1. acutifolia.
.S. rubellum, acutifolium, fmbriatum, Wulfanum.
2. cuspidata.
vS. cuspidatum, laxifolium, Lindbergii.
3. squarrosa.
6'. teres, squarrosum.
4. rigida.
6'. rigidum, Mulleri, Angstrbmii.