WILLIAMS: PERUVIAN MOSSES. 327 
Ollantaytambo, about 3,000 m., July, 1911, Foote 7. 
GRIMMIA MICRO-OVATA C. Mill. 
Temple of Viracocha near Tinta, on rock, about 3,500 m., 
April, 1915, Cook & Gilbert 206; Ollantaytambo, on rock, about 
3,000 m., May, 1915, Cook & Gilbert 600. 
GRIMMIA OVATA Web. & Mohr. 
Cuzco, on dry rock, about 3,500 m., 1911, Foote 8. 
Grimmia rivulariopsis sp. nov. 
_ Dioecious, the male plant rather more slender than the fertile 
with often 2~3 flowers scattered along the stem; the inner peri- 
gonial leaves small, ovate, ecostate, or faintly costate, enclosing 
rather numerous, fusiform antheridia about 0.5 mm. long, without 
paraphyses: fruiting-plants abundantly branching, 2-3 cm. high, 
without radicles and bearing slightly secund leaves, erect-spreading 
when moist, mostly somewhat incurved-appressed when dry; 
stem-leaves oblong-ovate, about 2 mm. long, rather abruptly 
narrowed to an acute, serrulate apex, the margins entire, of a 
double thickness of cells and recurved from a little below the 
apex to near the base; costa stout, percurrent, smooth on both 
Sides and flat or convex on the ventral side in the upper part; 
cells of stem-leaves distinct, smooth, with slightly thickened, 
scarcely or not sinuous walls, the median mostly 6 wide by 
6-8 u long, the basal more or less rectangular, 8 u wide by 1 6-22 u 
long; perichaetial leaves larger than those of the stem, about 
3-5 mm. long, the costa of the inner leaves rather faint below, 
widest toward the apex, not quite percurrent, the cells of the 
lower half of leaf narrowly rectangular or linear with slightly 
thickened, straight walls; capsule ovate, immersed, about 1.5 mm. 
high, without stomata, a band of five or six rows of small, trans- 
versely elongate cells about the rim, the median exothecal cells 
scarcely or not elongate, rather irregular with scarcely thickened 
or sinuous walls, up to 25 # in diameter; seta erect, scarcely one 
half the capsule in height; peristome-teeth lanceolate, about 120 u 
wide at the base and 400 x high, red, papillose, entire or often split 
at the apex or along the median line and slightly lacunose; annulus 
none; lid convex, obliquely apiculate; calyptra little more than 
covering the apiculus, the base cleft into several lobes. (PLATE 19.) 
Ollantaytambo, about 3,000 m., on rock in stream bed, May, 
1915, Cook & Gilbert 753; and on rock, same place and collectors, 
56r. 
Most closely related to G. amblyophyila C. Mill. of the South 
American species, but the apex of the leaf is very different, the 
