3S6 Williams: Mosses from west coast of South America 



here and there short lobes; calyptra cucullate, smooth, descending 

 well below the lid; spores rough, up to 25 n in diameter. 

 Peru: vicinity of Lima, July, 18774. 



PSEUDOCROSSIDIUM gen. nov. 



Dioicous. Small plants with simple or slightly branched 

 stems having a distinct central strand and leaves, when dry, erect- 

 appressed or sometimes twisted about the stem. Stem-leaves 

 with margins in the upper part once to twice revolute, the upper 

 side of the revolute part with cells often much inflated or with 

 greatly enlarged papillae. Costa broader in the upper part than 

 below, nearly pcrcurrent or excurrent; in cross-section about two 

 thirds up showing 5 to 8 guide cells, mostly in one row, beneath 

 them a large stereid band and on the upper side numerous lax, 

 thin-walled cells in i to 3 layers forming a continuous, densely 

 papillose surface or sometimes more or less broken up into filaments 

 2 or 3 cells high with the terminal cells papillose (occasionally, also, 

 a thin band of stereid cells just above the guide-cells in P. apicu- 

 latum). Cells of the upper part of leaf not or slightly elongate, 

 mostly obscure with crowded papillae on one or both sides, in the 

 lower part, smooth, pale, rectangular or short, more or less trans- 

 versely elongate. Perichaetial leaves greatly differentiated, the 

 2 or 3 inner much larger than those of the stem, convolute, pale 

 throughout, with narrow costa mostly vanishing below the obtuse 

 -or truncate, nearly or quite entire apex. Capsule nearly cylindric 

 •and erect with a slightly oblique, subulate lid. Peristome of 32 

 slender, papillose teeth twisted to the left, from a low basal mem- 

 ibrane. Annulus of 2 or 3 rows of persistent cells. Calyptra 

 cucullate. 



Type species, P. chilense. 



Pseudocrossidium chilense sp. nov. 



Evidently dioicous, the male flowers not found: plants in 

 brownish green cushions with somewhat branching stems, 2-4 mm. 

 high, with a very distinct central strand and walls of outer cells 

 scarcely thickened; stem-leaves erect-appressed when dry, more 

 or less broadly ovate, obtusely or acutely pointed, the upper about 



1 mm. k)ng, the lower shorter, rather deeply keeled above with 

 the margins strongly revolute half way down or more; costa 

 nearly percurrcnt, enlarged in the upper half, 120-140 m wide, in 

 cross-section above the middle showing 6 to 9 guide-cells mostly in 

 one row, below them a large stereid band and on the upper side 



2 or 3 layers of lax, thin-walled cells, those at the surface densely 

 papillose and sometimes more or less separated,- cells of upper 



