326 Williams: Peruvian mosses 



Mitten was correct, I believe, in thinking B. apiculata Hampe 

 not distinct from this species. 



Barbula subulatula C. Miill. 



Urubamba, on damp earth, 2,900 m., July, 1911, Foote 5. 



Tortula affinis Hampe. 



SicLiani, Vilcanota Valley, on stone, about 3,600 m., April, 

 191 5, Cook Gf Gilbert 157; Ollantaytambo, on rock, about 3,000 

 m., May, 1915, Cook & Gilbert 612; Urubamba, on rock, 2,900 m., 

 July, 191 1, Foote 6. 



Tortilla bipedicellata Besch. and T. confusa Card., I believe, do 

 not differ from T. affinis, which in turn is very close to T. pichin- 

 chensis (Tayl.) Mitt., differing chiefly in having a low basal mem- 

 brane of the peristome, the cell structure of which also varies. 

 In T. pichinchensis the cells are often as high as broad, and some- 

 what rhomboidal in slightly oblique rows; in T. affinis the cells 

 are low, mostly two or three times broader than high. 



Tortula andicola Mont. 



Ollantaytambo, about 3,000 m.. May, 1915, Cook & Gilbert 771. 



Tortula lacerifolia sp. nov. 



Dioecious: plants with stems (in this small collection scattered 

 through cushions of Fabronia andina) mostly simple, 6-8 mm. 

 high, with radicles at the base and leaves more or less aggregate 

 toward the apex; stem-leaves twisting incurved when dry, erect- 

 spreading when moist, oblong, mostly 2-2.5 mm. long, the margins 

 usually deeply incised in the upper half into readily separating, 

 narrow, irregular segments, often 0.25 mm. long and twisted part 

 way round or inflexed or reflexed, the margins of the lower leaf 

 being entire and recurved; costa golden-brown, stout, near the 

 base 80 jx wide, smooth on the back, more or less papillose on the 

 upper side, excurrent into a thorn-like spine, in cross-section 

 showing two large guide-cells, a large band of stereid cells on the 

 dorsal side, with two medium-sized cells on the ventral side; cells 

 throughout upper leaf rather obscure, mostly hexagonal, mamillose 

 and covered on both sides with small often C-shaped papillae, 

 those of lower leaf pale, with few or no papillae and mostly short- 

 rectangular, up to about 18^1 wide by 40-50^1 long; outer peri- 

 chaetial leaves like those of the stem, the inner small, pale, more 

 or less deeply cleft into numerous segments, the archegonia 

 numerous, with few paraphyses; fruit unknown. (Plate 18, 

 figs. 1-6.) 



