310 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
often reduced to two; a slender peduncle with narrowly linear paleae in the 
upper part; a disciform receptacle, coarsely tuberculate and scarcely convex, 
the lobes confluent throughout, the receptacle thus appearing without lobes; an 
involucre extending to the margin of the disk; an ovate, hyaline, horizontal 
pseudoperianth, scarcely extending beyond the disk; almost black spores, 108 p 
in diameter, with narrow rough wings; bispiral elaters, 230 uw long. 
Although nothing is said in the description about the length of the sexual 
branches, the fact that they are ventral in position would seem to indicate that 
this species, as well as the preceding, was related to A. elegans. In fact, the 
vegetative characters of I’. atrispora agree in all essential respects with those of 
A. lateralis, except that the air chambers are said to be without “ filaments.” 
If this means that no supplementary partitions are present, it might indicate a 
relationship with the A, tenella group, where the dorsal chambers remain un- 
divided; but the phrase by no means demands this interpretation and may 
simply mean that the supplementary partitions extend to the epidermis and do 
not look like free filaments in section view. Unfortunately the characters as- 
signed to the female receptacle—the almost flat and scarcely lobed disk—would 
seem to remove the species definitely from A, lateralis. These characters, how- 
ever, may be due to a poor development of the female plants. In A. elegans, 
for example, the lobes are often indistinct, even when ripe capsules are present, 
if the conditions have been unfavorable for full development; and the upper 
surface is not necessarily very convex, if the tubercles are left out of considera- 
tion. The writer would therefore suggest that F. atrispora be considered a 
possible synonym of A. lateralis, until its status can be adequately determined, 
3. FIMBRIARIA MEXICANA Stephani, Sp. Hep. 6:15. 1917. 
Mexico: Without definite locality, Frere Nicolds. 
The description of F. mexicana is open to the same criticism as that of F. 
arseniit and leaves the reader in much doubt regarding the essential features of 
the species. Here again the epidermis and the spores are completely neglected, 
and nothing is said about the air chambers except that the compact ventral 
tissue (costa) is much thicker than the green tissue (stratum anticum). In 
fact, the measurements given for thickness lead to curious deductions. <Ac- 
cording to these the thickness of the ventral tissue in the middle is 1 mm. while 
the entire thickness of the thallus in the same position is likewise 1 mm., thus 
leaving nothing at all for the green tissue and the epidermis. The thallus of 
F, mexicana is described as large, 2.5 em. long and 10 mm. wide, and the ventral 
scales are said to be large and purple, each with a single unusually large ap- 
pendage, measuring 3 X 3 mm., the apex being obtuse and the margin irregularly 
repand. The branches are stated to be lateral, rarely appearing as apical inno- 
vations, and the inflorescence is given as monoicous, with the antheridia borne 
on slender branches. The more important features associated with the female 
receptacle are the very large disk, measuring 10 mm. in width, with a minutely 
umbonate apex and 4 lobes; an obovate involucre, with a papulose cuticle; and 
an ovate pseudoperianth, equaling the involucre in length, 
In its large size F, mexicana is comparable with A. californica and A. rugosa,,. 
but the description gives little evidence of relatiopship with these species, in 
both of which a dichotomous type of branching prevails. Among the North 
American species characterized by a prevailingly ventral branching, A. elegans 
and its allies at once come to mind. In these species, however, with rare excep- 
tions, neither the thallus nor the disk of the female receptacle exceeds 5 mm. 
in width. The remarkable appendages of F. mexicana also, with their obtuse 
apices, are very different from anything in the A. elegans group, and in their 
