49 
Analytic Keys to the Species of Mosses. 
2. Peristome double. 
a. Capsule smooth when dry. 
Cilia wider than teeth. 0. exiguuin, 24. 
Cilia narrow. 
Capsule gradually narrowed to seta .... 0. pallens, 26. 
Capsule abruptly contracted to seta ... 0. psilocarpum, 23 
H j 
b. Capsule costate when dry. 
i. Abruptly contracted to seta , collum not evident. 
Leaves with simple papillae. 
Capsule exserted, teeth papillose , . . . 0. consiiuile, 21. 
Capsule subimmersed, teeth with oblique sinuous lines . 0. Hallii, 13. 
Leaves rough with very long forked papillae ... 0. Watsoni, 9. 
ii. Gradually narrowed to seta with evident collum. 
* Capsule exserted. 
[O. tenellum may be sought here.] 
Cilia 8, calyptra hairy.0. cylindricarpum, 22. 
Cilia 16, calyptra naked.0. pulcliellum, 27. 
* * Capsule immersed or nearly. 
Leaves with salient furcate papillae. 
Teeth papillose below, paler above, with longitudinal or 
sinuous lines, rarely perforate .... 0. al pest re, 11. - 
Teeth papillose throughout, often perforate along 
median line. 
Neck of capsule shriveling into a cup which receives the 
seta, capsule contracted below mouth ... 0. fallax, 17. 
Neck of capsule not becoming cupped, capsule not con¬ 
tracted below mouth.0. pumilum, Sw. 1 - 
Leaves with simple, often weak papillae. 
Capsule emergent, subcylindric (long cyl. when dry), 
little contracted below the mouth ... 0. tenellum, 20. 
Capsule immersed, obovate, contracted below mouth. 
Neck shrivelling into a cup, which receives the seta . 0. fallax, 17. 
Neck not becoming cupped .... 0. strangulatum, 19. 
Capsule immersed, not contracted. 
Capsule straw-colored, teeth dirty-reddish . . 0. Oliioense, 16. 
Capsule with yellow (not orange) bands, teeth orange, 
yellow or pale.0. pumilum Sw. 1 
1 Venturi: Husn. Muse. Gall. 179, pi. 49. 
4—A. & L. 
