176 BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



Perichaetial and comal leaves similar. 

 Leaves faintly papillose, costa narrow, sometimes ex- 

 current A. Maconnii, SS. 



Leaves strongly papillose, costa 30-40/^ wide, percurrent A. niralis, SS. 



ARCHIDIUM, p. 49. 

 Autoicous. 



Costa reaching to point of leaf . . . . A. Ohioense, 50. 



Costa often long excurrent ..... A. Hallii, 51.^ 



Paroicous. 



Leaves serrulate A. tenerrimum, 50. 



Leaves quite entire. 



Cells oval or rhombic A. Ravenelii, 50 



Cells quadrangular or quadrate ... A. longifolium, 50. 



MICROMITRIUM, p. 37. 



Spores 63// diameter, leaves serrate . . M. megalosporum, 37. 



Spores 25// diameter, nearly smooth, leaves serrate above M. Austini, 37. 

 Spores a little smaller, papillose, leaves nearly entire M. synoicum, 37. 



EPHEMERUM, p. 37. 



Leaves not costate E. serratum, 37. 



Leaves costate. 



Costa ending below or at apex .... E. cohaerens, 39. 



Costa excurrent. 

 Seta short, capsule acutely beaked . . E. stenopliyllum, 39. 

 Seta wanting, capsule blunt pointed. 

 Leaves gradually long-accuminate, slightly and 



irregularly serrate at apex . . . E. crassinervium, 38, 

 Leaves with a long hyaline spinulose arista E. spinulosum, 38. 



Leaves papillose both sides ... E. papillosum, 38 . 



Leaves long-spinulose on both sides , . . E. hystrix, 38. 



SPHiERANGIUM, p. 40. 



Leaves papillose on both faces . . . S. Scliimperianum, 41. 



Leaves smooth, or papillose on back. 



Margins reflexed, plants triquetrous . . . S. triquetrum, 41. 

 Margins almost plane, plants round or tetragonal. 



Lower leaves ecostate S. riifescens, 40. 



Lower leaves costate S. muticuin, 40. 



iSee also Appendix, no. 34. 



