290 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
long and 12 to 18 w wide, tapering slightly toward the blunt ends, usually 
with 2 spirals in the median portion for a variable distance and 1 at each end, 
sometimes with 1 to 4 rings instead of spirals at the ends, the walls between the 
turns of the spiral unpigmented or pale brown. 
A mountain species, growing on shaded banks; known only from the follow- 
ing collections: 
FEDERAL District oF Mexico: La Cima, alt. 3,000 meters, October 14, 1908, 
Barnes € Land 413 (Y.; type); same locality, July 17, 1908, Pringle 10682 in 
part (distributed in Pl. Mex., in admixture with Plagiochasma crenulatum 
Gottsche, under the name P, muenchianum Steph.). 
The material of this new species is unfortunately so scanty that it has been 
impossible to determine the inflorescence with certainty. Three clusters of 
antheridia were observed, all on a single plant, and a female receptacle was 
present on a neighboring thallus, but it was impossible to demonstrate any 
connection between them. The male inflorescence bears a strong resemblance to 
that of the dioicous A. californica, which perhaps adds to the probability that 
A. rugosa also may be dioicous, The species derives its name from the finely 
crinkled appearance of the thallus along the margin. In typical cases this is 
distinctly fluted and stands in sharp contrast to the smooth surface of the 
thallus throughout the remainder of its extent. 
In addition to the elongated male inflorescence, A. rugosa shares certain 
other features with A. californica, such as the large size of the thallus, the 
dichotomous branching, the green tissue with subdivided dorsal chambers, and 
the compact tissue with unpitted walls. There are, however, important differ- 
ential characters. In A. rugosa the epidermal cells have distinct trigones; the 
green tissue is very loose, the dorsal chambers being sparingly subdivided; the 
ventral scales show only 1 or (rarely) 2 anpendages; the disk of the recep- 
tacle is scarcely lobed; and the spores are brown, with the meshes of the fine 
surface network about 10 » across, and without coarse folds or ridges of any 
kind (except the marginal wings). In A. californica, on the other hand, the 
epidermal cells are thin-walled throughout or show very minute trigones; the 
green tissue is somewhat more compact, the dorsal chambers being more abun- 
dantly subdivided; the ventral scales show 2 to 4 appendages; the disk of the 
receptacle is deeply lobed; and the spores are yellow, with the meshes of the 
network only 3 to 4 wu across, and with additional coarse ridges on the spore 
faces. 
Among Mexican species it will be sufficient to compare A. rugosa with A. 
pringlet and A. venosa, both of which are distinctly smaller. In A. pringlei the 
green tissue, although somewhat more compact, shows no subdivision of the 
dorsal air chambers, each being clearly provided with an epidermal pore; the 
pores, moreover, are smaller, the appendages of the ventral scales are larger 
and usually more toothed, and the female receptacle is distinctly lobed. In 
A, venosa, which is perhaps the closest known ally of A. rugosa, the thallus is 
even more delicate; the inflorescence is paroicous; the disk of the receptacle is 
flatter, looser in texture, and usually lobed; the pseudoperianth is only 8 to 
10-cleft (instead of 12-cleft or more); the spores are paler and show a finer 
surface network, the meshes being mostly only 1 to 4 » wide; and the elaters 
are only 6 to 8 u» in diameter (instead of 12 to 18 pz). 
10. Asterella elegans (Spreng.) Trevis. 
Fimbriaria elegans Spreng. Syst. Veg. ed. 16. 47: 235. 1827, 
Marchantia physocarpa Bertero; Spreng. loc. cit., as synonym. 
Fimbriaria cub[anjensis Lehm.; Mont. in Sagra, Hist. Cuba 9: 489. pl. 
19, f. 8. 1845, 
