EVANS—THE NORTH AMERICAN SPECIES OF ASTERELLA. 295 
135 » in diameter, dark purple or nearly black with a reddish border, reticulated 
when young and opaque when old; the pseudoperianth is described as 8 to 
12-cleft with coherent divisions, the peduncle as 1 to 1.5 cm. high and pilose 
(especially at the apex), the elaters as bispiral, and the receptacle as convex, no 
tubercles being mentioned. 
In recognizing Underwood’s Cuban species Stephani discusses some of the 
features not alluded to in the original descriptions but brings out few addi- 
tional differential characters. To all three species (as well as to F, elegans) 
he assigns apical innovations and ventral branches, a photosynthetic tissue with 
hairs in the chambers, at least under the pores (but see, in this connection, 
p. 252), and a female receptacle with high tubercles or papules. The pores are 
said to be surrounded by 6 radiating series of cells, with 3 cells in each 
series in A. wrightii and A. austini, 4 or 5 in A. elegans, and 5 in A. cubensis. 
In A, cubensis the spores are described as 90 w in diameter, brownish red, with 
narrow papillate wings; in A. wrightii as 102 » in diameter, orange-colored, 
with broad and rough yellow wings; and in A. elegans as 100 w in diameter, 
reddish brown, with narrow and rough, entire wings; in A austini the spores are 
not described. With regard to the appendages of the ventral scales, Stephani 
states that 1 or 2 may be present in A. cubensis, implying a single appendage 
in the other cases. In all four species the appendages are said to be long and 
narrowly lanceolate or filiform, a single marginal spine being occasionally 
present in A. wrightii. The position of the male inflorescence at the apex of 
a ventral branch—short in A. elegans, short or long in the three Cuban species— 
is likewise noted. 
In order to show that the differences brought out by Underwood and Stephani 
are too slight and too inconstant, in the case of the Cuban species, to be con- 
sidered specific, it will perhaps be justifiable to discuss the characters of A. 
elegans, as understood by the writer, in some detail. The thallus varies 
greatly in size and general appearance according to the environment. In dry 
localities it is usually only 2 to 3 mm. in width and may be even less; in 
moist and shaded localities it sometimes attains a width of 6 mm, The broader 
forms are often thin and delicate, but the narrower forms may be equally so, 
although they tend to be firmer and more compact. The amount of pigmentation 
also is subject to great variation. At one extreme the plants are green through- 
out; at the other the pigmentation involves the ventral scales, the spaces be- 
tween the scales, the marginal portions of both surfaces, the peduncles and 
disks of the female receptacles, and the pseudoperianths. Even the dorsal 
surface of the thallus may be spotted or blotched with purple. The margins 
tend to become scarious with age but are not strongly incurved when dry, so 
that the species never presents a xerophytic appearance. 
Branching by forking occurs occasionally but is infrequent, especially after 
the formation of the sexual organs has begun. The branching then is almost 
invariably intercalary, sometimes by means of apical innovations, but usually 
by means of ventral outgrowths. The sexual branches themselves vary greatly 
in length and in width, but their growth is always brought to an end by the 
development of the receptacles, whether male or female. A sexual branch, 
however, especially if elongated, may give rise to an apical innovation or to 
lateral branches, these in turn bearing new receptacles. A sexual branch if 
elongated is usually relatively broad; if abbreviated, relatively narrow. In one 
observed instance a long branch bore a female receptacle and 6 lateral branches, 
4 of which (2 male and 2 female) were very short, while the other 2 (1 male 
and 1 female) were more elongated, though less than half the length of the 
original branch; one of the longer branches bore 2 short lateral branches 
