188 BULLETIN OP THE UNIVERSITY OF WISCONSIN. 



SELIGERIA, p. 96. 



Seta straight when moist. 

 Leaves sharp pointed, cells above rectangular, spores 



10-U/i S. pusilla, 96. 



Leaves blunt-pointed, cells above quadratic, spores 



14-18// S. calcarea, 97. 



Leaves mostly blunt-pointed, cells rectangular, spores 



24-32// S. tristicha, 97. 



-Seta arcuate when moist. 



Leaves long-subulate, costa excurrent . , . S. recurrata, 97. 

 Leaves sub-linear, obtuse, costa not excurrent S. campylopoda, 107. 



POTTIA, p. 100. 



I. Peristome wanting or rudimentary. 



Costa with 2-4 lamellge above P. cavifolia, 101. 



Costa not lamellate. 



Leaf margins more or less re volute. 

 Lid conic obtuse, spores echinate ... P. minatula, 101. 

 Lid rostellate, spores papillose. 

 Calyptra smooth. 

 Capsule obovate spherical (1 : 1) or sub-hemi- 

 spherical P. truiicata, 101. 



Capsule oblong-oval (1:2). 

 Leaves minutely papillose toward apex, basal 



cells 1:4 P. intermedia, 110. 



Leaves smooth, basal cells 1 : 5-6 . . P. littoralis, 111. 



Calyptra scabrous P. Wilsoni, 101. 



Leaf margins plane or involute. 

 Lid abruptly rostrate, leaves sharply serrate above P. Heiinii,^ 102. 

 Lid conic, leaves distantly denticulate above . P. riparia, 102. 



Lid conic-subulate, leaves slightly crenulate above P. Barbula, 102. 



II. Peristome distinct. 



Leaves oblong-lanceolate, margins revolute . . P. Starkeana, 103. 

 Leaves rounded or round-spatutate, margins plane P. latifolia, 103. 



iP. heimioides Kindb. (Appendix, no. 109), evidently falls here. The great resem- 

 blance of the two makes the specific value of P. heimioides extremely doubtful. 



