1899] Wille,— New forms of green algae 149 
cells, or frequently with only one layer and occasional groups of bistro- 
matic cells here and there, not papillose, but the thickened walls of the 
apical cells giving an irregular outline to the cross-sections of the leaves ; 
basal cells in one layer, more distinct, oblong or quadrate, .013—.02 1mm. 
in diameter. Dioicous, only male plants collected, antheridia large, 
bright yellow, with or without paraphyses. 
On rocks, Tuckerman's Ravine, Mt. Washington, N. H., alt. 1,230 
m. July 30, 1890. Collected by Dr. Alexander W. Evans of Yale 
University, to whom this species is dedicated in recognition of his ser- 
vices to American bryology. 
Dr. Evans’ specimens have been compared with Grimmia caespiti- 
cia (Brid.) Jur. (G. sulcata Sauter) and with Limpricht's description 
and figures (Rab. Kryptfl. 4: 2, 778, fig. 203). "Though closely re- 
sembling this species in the form and structure of the leaves, ours lack 
the two prominent folds of the European species and the plants are 
coarser and more loosely tufted. Dr. Breidler kindly sent me speci- 
mens from the Austrian Alps for comparison and I hereby tender him 
and Mr. J. F. Collins my thanks, the drawings having been made by 
Mr. Collins. 
EXPLANATION OF PLATE 7. — Grimmia Evansi: fig. 1, outlines of three foliage 
leaves, enlarged 12 diameters; fig. 2, perigonal leaves, flattened and torn on account 
of being very concave, enlarged 12 diameters; fig. 3, apical cells of one leaf with a 
hyaline tip; fig. 4, median cells; fig. 5, basal cells; fig. 6, alar cells; figs. 7 and 8, 
cross-sections of leaves, showing irregular bistromatic cells, Figs. 3 to 8 are enlarged 
330 diameters, 
NEW FORMS OF GREEN ALGAE.: 
N. WILLE. 
MICROSPORA AMOENA (Kuetz.) Rab., forma crassior, N. FORM. 
Cells 30-32 u diam.— Pequonnock River, Bridgeport, Conn., April 
22, 1894, in company with the type ; collected by Isaac Holden. 
RHIZOCLONIUM LACUSTRE Kuetz. forma Americana, N. FORM. Cells 
not swollen, with thin walls and very scanty rhizoids. Cells 15-16 y. 
wide, 15-60 y long. — Attached to stones, and growing to a length of 
one half meter to one meter, Bridgeport, Conn., July 25, 1892 ; col- 
lected by Isaac Holden. 
I The forms here described, with a number of others, all of which were intended 
for distribution in Collins, Holden, and Setchell, Phycotheca Boreali-Americana, were 
submitted to Professor Wille for revision, and these two forms and one species from 
New England were determined by him to be new. They will be distributed in Fascicle 
XIII, which will appear some time in 1899. — F. S. COLLINS. 
