NortH AMERICAN SPECIES OF LESKEA 469 
and narrower opercula and by its rhombic, elongated leaf-cells. 
In its general appearance it resembles some forms of Z. polycarpa 
paludosa, from which it is however easily separated by the char- 
acters just named. When once understood it will probably be 
found more common than here indicated. 
5. LesKEA GRACILEsceNS Hedw. Spec. Musc. 222. p/. 56, f. 8-13. 
1801. 
Leskea titermedia olim mihi. 
In intricate spreading tufts, pale to dark green passing to red- 
dish-brown or blackish ; stems 2-4 cm. long, creeping, radiculose, 
pinnately branched ; central strand rudimentary or none; branches 
simple, erect, often subjulaceous: paraphyllia few, lanceolate, 
rarely none: stem-leaves appressed-imbricated when dry, erect- 
spreading when moist, 0.4-0.5 mm. wide, 0.65-0.9 mm. long, 
ovate, gradually acute, obtuse or blunt-pointed, straight, lightly 
biplicate, margins entire, often more or less revolute, costa sub- 
percurrent ; branch-leaves similar, not plicate ; leaf-cells somewhat 
uniform, unipapillate on lower surface, usually smooth on upper ; 
median quadrate-hexagonal, 8~10 » broad; alar and basal quad- 
rate; apical roundish: monoicous: perichetial bracts erect, striate, 
blunt, inner subvaginant, costate ; pedicel 8-10 mm. long; cap- 
sule erect, oblong-cylindric, tapering at base, substriate and red- 
dish when empty ; urn 1.5—2 mm. long, 0.6 mm. wide ; exothe- 
cial cells oblong, a few rows of roundish cells about the mouth ; 
annulus of two rows of cells, deciduous ; teeth whitish, lanceolate- 
linear, divisural line faint, lamellate, 0.35-0.45 mm. long; endo- 
stomial band about one quarter the length of the teeth ; segments 
linear, usually shorter than the teeth, carinate, open, sometimes 
poorly developed and unequal; cilia none; operculum conic, ob- 
tuse or acute ; calyptra smooth, cucullate ; spores smooth, 8-11 y, 
mature in early summer. On the base of trees, rotten wood, 
stones and the ground. 
Type tocatity: Pennsylvania; duplicate of type in the 
Academy of Natural Sciences of Philadelphia.* 
*M. Cardot, who has made a careful study of Hedwig’s types of American Mosses 
as found in Herb. Boissier, informs me that Z. gracilescens is not among them. In 
the Muhlenberg collection, now in possession of the Academy of Natural Sciences of 
Philadelphia, there are, however, a number of specimens so named, either positively or 
questionably, It is probable that one of these is a duplicate of the type, but which one 
can only be conjectured, since there are no indications pointing to this fact. These 
specimens, as also those of Z. oéscura in the same collection, make it evident that 
Hedwig, after founding these species, failed to recognize their distinguishing characters, 
as nearly all of Muh'enberg’s later collections are named either ‘‘ Z. gracilescens ?’’ or 
