— 399 — 
7.P.Ravenelii Austin. 
»Differs from P. subulatum: Upper leaves with longer sub- 
lanceolate base; costa excurrent. Capsule broadly apiculate, a 
little larger. — Light sandy soil r; Amer. U. S.»: Lesq. et Jam. 
162. Arehidium Bridel, 
A. Monoecious with male flowers on sepasela beanies 
Leaf-cells subrectangular. 
1.A.ohioénse Schimper; Sullivant icon. muse. 
Leaves distant patent sublinear-subulate serrulate above; the 
perichetial from ovate base abruptly acuminate; costa gen. not. 
excurrent. — Clay soil r. Amer. Can.: Macoun. 
2.A.Hallii Austin. 
_ Leaves crowded suberect sublinear-subulate nearly entire; costa 
sometimes excurrent.  Perichetial leaves not seen. — Amer, r. 
U. S.: Henry, com. Cardot. 
B. Synoecious or subparoecious (submonoecious). 
3.A.alternifolium Hooker et Taylor. — Phascura H. T.; Ar- 
chidium Schimper; A. phascoides Brid. 
Leaves distant patent sublinear-subulate gen. entire; cells sub- 
rectangular; perichetial leaves from ovate-oblong base abruptly 
acuminate; costa sometimes excurrent. Stem with numerous 
flagelliform shoots. Habit of Pleuridium alternifolium, -- Wet 
soil viz. near lakes r. Eur. Sweden: France: Berthoumieu. 
4.A.longifolium Lesquereux et James. 
»Synoecious. Leaves narrowly lanceolate-subulate; cells gen. 
rectangular; costa excurrent. — Amer. r. U. S.»: Lesq. et Jam. 
5.A.tenerrimum Mitten. 
»Differs from B. ohioénse: Subparoecious. Leaf-cells much 
shorter and closer. — Amer. r. U. S.: Drummond»: Lesq. 
et Jam... . 
6.A.Ravenelii Austin. 
»Synoecious. Lower leaves ovate, upper ovate-lanceolate or 
acute or obtuse entire; cells round-oval or rhomboidal; costa 
sometimes excurrent. — Amer. r. U. S.»: Lesq. et Jam. 
163. Ephemerum Hampe. 
1. Eeostata. Leaves nerveless (r. faintly costate in upper 
half.). 
2. Costata. Leaves costate. Spores papillose. 
1. Ecostata. 
A. Leaves serrate above middle; cells wide. 
1.E.serratum Schreber. — Phascum Schr.; Ephemerum Hampe. 
Leaves narrowly suboblong not long-acuminate. Spores pa- 
