24 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
less recurved and slightly serrulate one-third the way down; cells throughout upper 
leaf elongate with somewhat unequally thickened, slightly sinuous walls; median 
cells about 5 » wide by 20 to 35 » long, toward the base rather larger and cell walls 
pitted near the insertion of the leaf toward the costa; cells at basal angles numerous, 
short, often transversely elongate and extending some distance upward; outer peri- 
cheetial leaves short; the inner oblong-lanceolate, 6 or 7 mm. long, convolute nearly 
to the acute entire apex and extending to above the middle of seta, sometimes nearly 
to the base of the capsule; seta 7 to 9 mm. long with erect oval capsule 2.5 mm long, 
bearing a conical-apiculate or short-rostrate lid about 1 mm. long; annules wanting; 
peristome double, the outer of pale, papillose to nearly smooth, rather irregular teeth 
with indistinct articulations, separate to below rim of capsule and solid, or more or 
less pertuse along median line; inner peristome a low, pale membrane scarcely one- 
fifth the teeth in height, with margin nearly entire; spores not quite smooth, roundish 
(80 » in diameter) to oblong (up to 120 » long). 
Type Locauiry: Vicinity of Camp Aguacatal, eastern slope of Chiriqui Volcano, 
Chiriqui, Panama, altitude 2,100 to 2,300 meters, March 10 to 13, 1911, Mazon 5276. 
On tree trunks. 
Disrripution: Chiriqui Volcano, Panama, to valley of Mexico (Schaffner, 1875) 
and San Luis Potosi, Mexico (Schaffner 340 in 1879). 
This species in habit much resembles L. cryptotheca, but is rather smaller and with 
leaves more pointed. 
Thamnium cobanense (C. Miiller), R. S. Williams. 
Porotrichum cobanense ©. Miiller, Bull. Herb. Boiss, 5: 202. 1897. 
The specimens at hand were collected from tree trunks in a moist ravine above El 
Potrero Camp, Chiriqui Volcano, Chiriqui, Panama, altitude 2,890 to 3,025 meters, 
March 12, 1911, by William R. Maxon (no, 5330). They are in fine fruit, the fruiting 
state hitherto unknown, I believe. The species isdioicous. It has perichetial leaves 
nearly or quite ecostate and entire, the inner abruptly narrowed to a smooth point 
about one-third the entire length; seta 15 to 18 mm. high, curved; capsule oblong, 
about 2.5 mm. long, slightly contracted under the mouth when dry; annulus of 2 
or 3 rows of cells; lid convex, obliquely rostrate, about 1.5mm. long; outer peristome 
with teeth finely cross-striate over half way up from base, in upper part paler and 
papillose; inner peristome pale brown like outer, the segments from high basilar 
membrane, pertuse along median line with one or mostly two smooth cilia between; 
spores nearly smooth, 12 to 14 » in diamater. 
Type LocaLiry: Guatemala, 
DistRIBUTION: Guatemala and Panama. 
Cyclodictyon maxoni R.§. Williams, sp. nov. 
* Flowers and fruit unknown; plants in lax dusky brown tufts, green only at the tips 
of the branches, the stems mostly denuded of leaves below, 6 to 8 cm. long, and bearing 
rather numerous irregular branches; leaves, when dry, spreading-incurved or loosely 
imbricate, about 1.6 mm. long, broadly ovate, very concave, with flat, entire or 
nearly entire margins and with the apex broad and rounded or scarcely acutely 
pointed; leaves bicostate, the costze nearly or quite smooth on the back, extending 
usually four-fifths the length of the leaf; leaf cells smooth on both sides, elongate- 
hexagonal to oblong or linear, a little below apex about 5 « wide by 20 » long, gradu- 
ally longer below, up to 50 or 60 « long toward base with about 2 rows of short brown 
cells extending across the base at insertion of leaf, the marginal cells a little longer and 
narrower than within but not forming a distinct border; cell walls thin, not pitted. 
Type Locatiry: Humid forest along the upper Caldera River, near ‘‘Camp I,” 
Holcomb’s trail, above El Boquete, Chiriqui, altitude 1,450 to 1,650 meters, March 22 
to 24, 1911, Mazon 5619. On stones in bed of swift current, mostly submerged. 
DistRIBUTION: Known only from the type collection. 
This species seems to be nearest C’. obscurifolium (Mitt.) Broth., but the latter has a 
shorter, broader, and more pointed leaf with a distinct border. 
