EVANS—THE NORTH AMERICAN SPECIES OF ASTERELLA. 8038 
ends, usually bispiral in the middle for a variable distance and unispiral at the 
ends, rarely unispiral throughout. 
On rocks; known only from the following locality : 
Cusa: Monte Verde, Yateras, March 18, 1860, Wright (H., Y.). 
It is with considerable hesitation that the writer proposes a jew species on a 
single collection, more especially since this new species is closely allied to the 
variable A. elegans. There is, however, so marked a difference in the spore 
markings that this course appears justifiable. In A, elegans the wings and 
ridges of the spores are thin and wide and inclose a fairly regular reticulum 
with the meshes mostly 15 to 20 » wide; in A. reticulata the wings (except 
those along the edges of the pyramid) are thick and narrow and inclose an 
irregular reticulum with smaller meshes, mostly 8 to 12 » wide. The margins 
of the wings and ridges are marked by very irregular fine lines which tend to 
run parallel around the meshes but often deviate from one another and leave 
minute spaces or interstices of varying sizes. It has already been pointed out 
that the wings and ridges in A. elegans show a tendency to broaden out on their 
edges, but the condition is even more striking in the new species, In addition 
to the differences derived from the spores, the female receptacle of A. reticulata 
is covered over with shorter tubercles than that of A. elegans, approaching in 
this respect the Mexican A. lateralis. 
The inflorescence of the new species has not been determined with certainty. 
The two male inflorescences observed were borne on elongated branches but, 
although female receptacles were present in the vicinity, it was impossible to 
demonstrate a connection between them. If the species could be proved dioicous, 
this would afford another important character, helping to distinguish it from 
A. elegans; it is more probable, however, that the species is autoicous and that 
the male inflorescences become difficult to detect by the time the capsules are 
mature. 
Aside from the differences already noted, A. reticulata and A. elegans are 
strikingly alike. In general appearance, in the minute structure of the thallus, 
in the form of the ventral scales and their appendages, in the male inflorescence, 
in the pseudoperianths, and in the elaters no differences of any significance 
have been detected. The new species, to be sure, presents a somewhat xero- 
phytic appearance, the margins of the thallus tending to be incurved when dry, 
but this feature is too inconstant to be emphasized, since the margins of the 
thallus in A. elegans are sometimes incurved to a slight degree. 
14. Asterella bolanderi (Austin) Underw. 
Fimbriaria bolanderi Austin, Proc, Acad. Phila. 1869: 230, 1869. 
Fimbriaria violacea Austin, loe. cit., as a synonym of F. echinella ; Bull, Tor- 
rey Club 3: 17. 1872. 
Asterella bolanderi Underw. Bot. Gaz. 20: 61. 1895. 
Asterella violacea Underw. loc. cit. 
Thallus much like that of A. lateralis, green or yellowish green above, the mar- 
gins and ventral surface usually more or less pigmented with purple, the margins 
strongly incurved when dry, mostly 1 to 2 cm, long and 2 to 4 mm. wide, rarely 
forking, almost always with ventral branches and apical innovations, the sexual 
branches ventral and very short, rarely if ever innovating; epidermis composed 
of cells with somewhat thickened walls and sometimes with minute trigones, 
averaging about 40 X 28 uw; pores distinctly elevated, measuring (with their sur- 
rounding cells) mostly 110 to 150 » in length and 70 to 110 w in width, sur- 
rounded usually by 7 or 8 (rarely 6 or 9) radiating series of cells with 3 (some- 
times 2 or 4) cells in each series, the radial walls slightly thickened; cells con- 
