10 C. M. Cooke, Jr.—The Hawaiian Hepaticce 
axillary to the underleaves (very unusual): rhizoids not abundant : 
leaves distant or subimbricated, transversely inserted, undivided : 
underleaves a little smaller than the leaves, undivided : leaf-cells 
with thickened walls : sexual branches intercalary, arising singly in 
the axils of the underleaves: 9 branch very short, its leaves reduced 
to the three to five rows of bracts; perianth long and _ slender, 
the three keels distinct except at the cylindrical base, separated 
by grooves; unfertilized archegonia borne at the base of calyptra : 
é spike oblong ; bracts in several pairs, strongly concave ; antheridia 
occurring singly ; paraphyses wanting; bracteoles similar to the 
underleaves but smaller : sporophyte not seen.» 
Acromastigum integrifolium (Aust.) Evans. 
Mastigobryum ? integrifolium Aust., Bot. Gazette, i, 32, 1875. 
Bazzania ? integrifolia Evans, Trans. Conn. Acad., viii, 255, 1892. 
Acromastigum integrifolium Hvans, Bull. Torr. Club, xxvii, 103, pl. I, 1900. 
Dioicous: general characters of stems and branches given above ; 
rhizoids whitish, simple or irregularly branched at the ends, very 
scanty on ordinary vegetative axes and occurring singly or in small 
clusters at the bases of some of the underleaves, more abundant on 
the flagella and less definite in position: leaves spreading widely 
from the stem, usually curved upward in the outer parts, ovate from 
a broad base, obtuse or more commonly acute, entire or nearly so, 
rarely with an indistinct angular tooth near apex: underleaves 
strongly squarrose, ovate or oblong, truncate or rounded at apex, 
entire or nearly so: leaf-cells with a very thick verruculose cuticle 
and conspicuous often confluent trigones but no intermediate thick- 
enings; cell-cavities stellate: bracts very small and similar to 
ordinary leaves at base of branch but becoming rapidly larger 
toward the perianth ; innermost bracts broadly ovate, gradually 
narrowed from near the base, shortly dentate or laciniate at apex 
(usually less than one-fourth the length) with slender teeth, other- 
wise entire or nearly so; innermost bracteole similar; perianth 
linear-fusiform, composed of a single layer of cells except at the 
very base, cells more uniformly thickened than the leaf-cells, mouth 
of perianth contracted, laciniate, the lacinie long and slender, 
straight or irregularly curved and distorted, sometimes denticulate, 
composed of a single row of cells above and usually two or more 
toward the base : ¢ bracts in about 6 pairs, strongly concave, ovate, 
shortly bi- or tri-denticulate at the apex, the teeth 1 to 3 cells 
