Williams: Mosses from west coast of South America 397 



part of leaf scarcely elongate, about 6 m in diameter, more or less 

 papillose on both sides, in lower part, paler, smooth, mostly nearly 

 square to transversely elongate, often 12X12^; perichaetial 

 leaves projecting well above those of the stem, the 2 or 3 inner 

 convolute, about 2 mm. long, mostly broadly rounded or truncate 

 at the entire or nearly entire apex, the leaf-cells mostly slightly 

 elongate throughout with lax, thin walls, smooth or finely papillose 

 on the back in the upper part; seta erect, about i cm. long; 

 capsule cylindric, about 2.25 mm. long without lid, the stoutly 

 beaked lid nearly erect, i mm. long, with the elongate cells in 

 oblique rows; peristome of 32 slender papillose teeth, twisted 

 about one half around to the left, from a rather low basal mem- 

 brane; annulus of 2 or 3 rows of small cells; calyptra cucuUate, 

 smooth; spores smooth, about 10 /j. in diameter. 



Chile: near Valparaiso, September ipij2b. 

 Pseudocrossidium apiculatum sp. nov. 



Dioicous, the outer perigonal leaves like those of the upper 

 stem, the inner much shorter, broadly ovate, with narrow costa, 

 enclosing numerous antheridia, 0.4 mm. long, and abundant, 

 slightly club-shaped paraphyses: plants in compact, greenish 

 brown mats with mostly simple stems i cm. high, with large, 

 very distinct central stand and outer walls of i or 2 rows of rather 

 small cells with scarcely thickened cell-walls; stem-leaves ovate- 

 lanceolate, acute, the upper about 1.5 mm. long, appressed and 

 mostly twisted about the stem when dry, the margins in the upper 

 half often twice revolute; costa excurrent, apiculate, in the widest 

 part 140-160 fjL across, in cross-section showing 6 to 8 guide cells, 

 below them a large stereid band and on the upper side 3 or 4 layers 

 of lax, thin-walled cells forming a compact densely papillose surface 

 or broken up into distinct filaments 2 or 3 cells high with the 

 terminal cell papillose (sometimes also a thin band of stereid cells 

 occurs just above the guide-cells) ; cells of upper leaf mostly not 

 elongate or transversely elongate, often 12 X 12 /i, papillose on 

 both sides, those of the revolute part often much inflated or with 

 greatly enlarged papillae on the upper face; lower cells of leaf 

 paler, mostly rectangular, 12-16^1 wide and 20-40 /x long; peri- 

 chaetial leaves pale, convolute, the inner 2.5 mm. long or more, 

 projecting well above the stem-leaves, somewhat obovate to 

 oblong, the apex obtusely rounded and more or less erose, the 

 costa narrow and vanishing a little below the apex; fruit unknown. 



Peru: above Arequipa, August, iSgy^. 



[Pseudocrossidium excavatum (Mitt.) comb. nov. 



To this genus I would also refer Tortula excavata Mitt. Jour. 



