14 
Wisconsin Academy of Sciences , Arts and Letters. 
ANALYTIC KEY 
TO THE 
GENERA OE MOSSES. 
Order I.— Sphagnaceae. 
Oapsule dehiscing by a deciduous operculum, peristome 
none, leaves composed of large hyaline cells, with 
intervening rows of small chlorophyllose ones. 
Genus single. Sphagnum, 12. 24. 
Order II.— Andreseacese. 
Capsule dehiscing by four (rarely six) longitudinal slits. 
Genus single. Andre sea, 25. 20. 
Order III.—Archidiacese. 
Capsule bursting irregularly, spores few and very large. 
Genus single. Archidium, 49. 28. 
Order IV.—Bryacese. 
Capsule bursting irregularly (spores numerous) or gen¬ 
erally dehiscing by a deciduous operculum, in the 
latter case usually furnished with a peristome. 
Leaves not sphagnoid. 
Genera numerous as follows: 
I. CLEISTOCARPI.— Capsule without a deciduous operculum. 
A. Green protonema persistent. 
Leaves ecostate. t 
Capsule colorless. Micromitrium, 37. 26* 
Capsule colored. Epliemerum, 37. 26. 
Leaves costate ... . Epliemerum, 37. 26. 
