EVANS—THE NORTH AMERICAN SPECIES OF ASTERELLA. 275 
oblong-conical or ovate-conical receptacle, borne on a naked peduncle; to the 
white pseudoperianth, with segments coherent at the apex; and to the brown 
spores, indistinctly granulose-papillose. In stating that the female receptacle 
is 5-fruited, however, he makes no allowance for variation, and he fails to 
make enough allowance when he describes the segments of the pseudoperianth 
as § to 10 in number. , 
When Howe proposed his Fimbriaria nudata as a new species he recognized 
its close relationship to F. palmeri but felt justified in separating it, largely 
because it usually had a 8 or 4-fruited receptacle and a pseudoperianth with 
10 or 11 divisions. Both Underwood and Stephani considered Howe’s species 
valid, but Howe himself, after studying authentic material of F. palmeri, de- 
cided that Austin’s species and his own were synonyms, a decision with which 
the writer fully agrees. Howe’s description and figures of Asterella palmert* 
show most of the important features with great clearness, He mentions, among 
other details not noted by Austin, the group of antheridia close to the peduncle 
of the female receptacle, the nearly smooth surface of the receptacle, the cir- 
cumscissile capsule, and the measurements of the spores and elaters. Stephani 
supplies a few additional data about the epidermal pores and ventral scales 
and alludes especially to the high and narrow air chambers of the dorsal layer. 
In the case of F. nudata he compares the structure of the green tissue with that 
of Riccia, associating it with a dry climate which prevents the development of 
a flat and thin thallus. 
On the whole the xerophytism of A. palmert is much more distinct than that 
of A. pringlei. It shows itself not only in the narrow air chambers of the green 
tissue but also in the strong involution of the thallus when dry and in the rela- 
tively larger ventral scales. When teeth are present on the appendages, the 
scales bear a certain resemblance to those of A. pringlei, the teeth in both species 
representing the stalks of slime papillae. But the papillae are very ephemeral 
in A. palmeri and the teeth tend to be fewer and shorter than in A. pringlet, 
in many cases being absent altogether. The teeth usually diverge but slightly 
and are sometimes detected with difficulty. 
The tendency of the spores to cling together in masses until late in the de- 
velopment of the capsule is alluded to by Howe. Usually under such circum- 
stances the spores are somewhat arrested in their growth and fail to show the 
markings in a typical manner. When well developed the ridges of the spore sur- 
face are very distinctive, being low and rounded, instead of high and sharp as 
in most species of Asterella where equally coarse markings are present. The 
folds are very irregular and often anastomose, sometimes inclosing small areas, 
but the surface never shows a distinct reticulum, even when these inclosed 
areas are numerous; it is much more likely to be convolute in appearance.. 
The wings along the edges of the spore are scarcely different from the folds. 
Aside from the differences already mentioned, A. palmeri differs from A. 
pringlei in its paroicous inflorescence, agreeing in this respect with both A. 
tenella and A. ludwigii. Its more xerophytic structure will at once distinguish 
it from both these species, where the green tissue is very loose and the thallus 
shows little tendency to become involute when dry. It is further distinguished 
by the thickened radial walls in the circle of cells around the epidermal pores, 
by the conical female receptacle, by the pseudoperianths extending vertically 
downward, by the coherent segments of the pseudoperianths, and by the much 
darker spores, the spherical faces of which are not covered over by a coarse 
reticulum. 
*Mem. Torrey Club 7: 55. pl. 99, f. 1-15. 1899. 
