EVANS: HEPATICAE OF PuERTO RICO 555 
cells wide at the base, the inner (proximal) tooth shorter, blunter 
and frequently obsolete, sinus long and shallow, forming an acute 
angle with the keel, hyaline papilla marginal, situated near the 
proximal base of the apical tooth, often reflexed and hidden within 
the water-sac ; cells of lobe averaging 14 at the margin, 28x 214 
in the middle, and 35 x 28 y at the base, slightly convex, thin- 
walled but with distinct local thickenings, the trigones circular or 
vaguely triangular in outline, the intermediate thickenings numer- 
ous, circular, sometimes two or even three between two trigones; 
ocelli none : underleaves distant to subimbricated, orbicular, plane 
or nearly so, 0.35 mm. long, cuneate toward the base and dis- 
tinctly short-decurrent on both sides, line of attachment somewhat 
arched, apex broad and more or less retuse, margin entire or 
nearly so: inflorescence autoicous: @ inflorescence sometimes 
borne on the main stem or on a leading branch but usually on a 
More or less abbreviated branch, without innovation; one or 
several pairs of leaves below the involucre intermediate in char- 
acter between the bracts and normal leaves; bracts obliquely 
spreading, the lobe ovate-lanceolate, 1-1.4 mm. long, 0.45—0.6 mm. 
Wide, subacute to acuminate, antical margin distinctly out- 
wardly curved, postical margin less curved or nearly straight, 
Margin entire or irregularly dentate in the upper part; lobule 
Consisting of a narrow, more or less inflated fold at the base 
ol the lobe, measuring about 0.5 x 0.09 mm., margin passing 
very gradually into the postical margin of the lobe without a 
distinct apex, entire ; bracteole free, plane or nearly so, ovate, 
9.75-0.85 mm. long, 0.4-0.5 mm. wide, gradually narrowed toward 
the apex, bifid about one tenth with erect, acute and often con- 
hivent teeth separated by a narrow sinus, margin entire or irregu- 
larly sinuate to dentate in the upper part ; perianth less than half 
€xserted, obovate in outline from a narrow base, measuring 
'X 0.75 mm. when well grown, apex broad, truncate to retuse 
With a distinct beak variable in length, trigonous, with sharp 
lateral keels and a high and narrow postical keel extending from 
the apex to the middle or below, antical surface plane or nearly 
80, lateral keels sometimes narrowly and interruptedly alate, the 
Wing entire or sparingly and irregularly sinuate or dentate: 
o inflorescence terminal, often on a leading branch ; bracts mostly 
n from three to six pairs, imbricated, diandrous, shortly and 
Uequally bifid with obtuse to acute divisions, the lobe ovate- 
oblong or ovate-ligulate, the lobule ovate, keel arched ; bracteoles 
imbricated, extending along the whole length of the spike, orbic- 
F tO. ovate, retuse to bidentate at the apex with rounded to 
as divisions : mature sporophyte not seen (PLATE 33, FIGURES 
~12), 
