172 LEJEUNEAE OF THE UNITED STATES AND CANADA 
appressed to lobe, bearing an acute tooth beyond the middle, then 
obliquely truncate to end of keel with a tooth composed of two 
rounded cells midway between the acute tooth and end of keel; 
stylus inconspicuous and soon obsolete, composed of two or rarely 
of three cells in a row, sometimes reduced to a one-celled papilla; 
cells of lobe thin-walled with small but distinct trigones and occa- 
sional intermediate thickenings averaging 10 in diameter at edge 
of lobe, 20 in the middle and 25 x 20 at the base, walls on 
outer surface of lobe slightly convex, each cell, except those near 
the base, bearing a single, large, short-cylindrical, rounded pro- 
jection, representing a local thickening of the wall: inflorescence 
dioicous: $ inflorescence borne on a leading branch innovating | 
on one side; bracts complicate, unequally bifid, the lobe similar to — 
the leaf-lobes but narrower, 0.6 mm. long, 0.3 mm. wide, lobule 
ovate, 0.35 mm. long, 0.17 mm. wide, apiculate or’ subacuminate 
at apex, margin and cells of lobe as in leaves ; perianth exserted, 
obconic in lower part, rectangular-oblong above, o 75 mm. long, 
0.3 mm. wide, slightly compressed, subtruncate at apex, sharply — 
five-keeled, the entire surface except near the base roughened as  — 
in leaves: 3 inflorescence unknown. ee 
On maple bark. British Columbia (Macoun), the type-locality. 
Exsic.: Hep. Amer. 177 (as Lejeunea (Colo-Lej.) Macounú). 
Spruce's original description of C. Macounii, which was pub- — — 
lished by Underwood, is so complete that very little has been e 
added to it. In fact the characters of the perianth as stated above 
are taken wholly from this description, the perianths in the speci- 
mens examined by the writer being either too young or too old to — P 
show these characters clearly. 
In its rough leaves C. Macounii resembles C. Biddlecomiae, but 
in the latter species the roughness is due mainly to the very con- 
vex or conical cell walls, while in C. Macounii it is due almost en- 
edes the globose warts on the cells. In C. Macouni also the — | 
lobe is rounded at the apex with its broadest part above the 
middle, while in C. Bidalecomiae the lobe is more or less sharply 
pointed with its broadest part below the middle. There are also 
differences in the marginal teeth of the lobule. ex 
in " interesting note to Underwood, Spruce compares Ce r 
~. with two autoicous species of tropical America—C. car 
1 P a (Mont) and C. platyneura (Spruce). Both of these | 
species differ in their compressed perianth with a low, bluntly two- 
angled, postical keel, which is almost obliterated at maturity. € 
