204 



BULLETIN or THE UNIVEESITT OF WISCONSIN. 



Cilia of a single row of cells or double at the base 

 Capsule immersed or emergent. 



Teeth, papillose, not vermicular striate 



Teeth vermicular striate, not papillose 

 Capsule exserted. 



Teeth not papillose . . . . . 



Teeth minutely papillose .... 



0. affine, 168. 

 0. fasti^iatam, SI4.. 



0, Blyttli, SS9. 

 0. praemorsum, S2e. 



c. Capsule ribbed only near the mouth. 



0. rnpestre, 167. 

 0. Eilliasil, 525. 



0. Bolanderi, 167. 



Teeth erect when dry. 

 Papillae of leaves simple, minute 

 Papillae of leaves bifurcate, salient 

 Teeth reflexed when dry. 



Upper part of leaf bistratose, teeth transversely lin- 

 eolate . . ...... 



Upper part of leaf unistratose, teeth very papUlose. 

 Teeth when dry reflexed and applied to capsule 0. elegans, S^. 



Teeth when dry touching capsule only with tip 0. speciosnm,'^ 169. 



Three little known and unimportant species from Greenland (Mac. Cat. 

 88): 00. JBreutelii Hpe., Barthii Sendtn., and Cfroenlandieum Bergg., 

 belonging to the division with superficial stomata are not included in the 

 key. According to Venturi in Husn. Muse. Grail. 175, the first two are 

 only forms of O. Blyttii. 



II. Stomata immersed. 

 1. Peristom,e simple, capsule costate. 



IJeaves obtuse, capsule immersed or emergent 



leaves acute or acuminate. 



Capsule long exserted, teeth erect when dry 

 Capsule half-emergent, teeth spreading when dry 

 [O. Balm may be sought here.] 



0. Jamesiannm, 177. 



0. anomalnm, 16i. 

 0. cnpulatam, 165. 



a. 



2. Peristome double. 

 Capsule smooth when dry. 



Cilia wider than teeth 



CUia narrow. 

 Capsule gradually narrowed to seta 

 Capsule abruptly contracted to seta 



0. exignnm, 174. 



0. pallens, 175. 

 0. pnsillum Mitt.' 173. 



1 See Appendix, no. 223. 

 * O. psilocarpum James. 



