Evans: HEpPATICAE OF PuERTO RICO 503 
trustworthy. It may be added to these that the leaves of Z. 
elliptica are usually from 8 to 12 cells broad, while those of Z. 
exocellata are from 12 to 15 cells. The underleaves of the latter 
species also are rounded below instead of angular, and their 
slender divisions spread less widely and have more bulging cells 
than in L. elliptica. 
LEPTOLEJEUNEA STENOPHYLLA (Lindenb. & Gottsche) Schiffn. 
Leeunea stenophylla Lindenb. & Gottsche; G. L. & N. Syn. 
Hep. 769. 1847. 
Colura stenophylla Trevis, Mem. r. Ist. Lomb. III. 4: 402. 
1877. 
Lejeunea (Lepto-Lejeunea) stenophylla Steph. Hedwigia, 29: 
96. 1890. 
Leptolejeunea stenophylla Schiffr. Engler’s Bot. Jahrb. 23: 
596. 1897, 
Pale green, becoming yellowish or brownish upon drying ; 
stems 0.035 mm. in diameter, closely adherent to substratum, 
irregularly once or twice pinnate with widely spreading branches: 
leaves distant, the lobe obliquely spreading, plane or somewhat 
revolute along antical margin, straight or upwardly curved near 
the apex, lanceolate, 0.5 mm. long, 0.13 mm. wide, somewhat 
Narrowed toward the base and attached by an almost longitudinal 
line of insertion, margin entire or very slightly crenulate or dentic- 
ulate from projecting cells, apex acute or short acuminate : 
lobule ovate, strongly inflated, 0.12 mm. long, 0.09 mm. wide, 
keel slightly arched, smooth or nearly so, usually continuous 
with postical margin of lobe, free margin plane or strongly involute 
too, or including the apex, then lunulate to end of keel, apex 
formed bya single cell so strongly curved as to almost touch the 
end of the keel, forming in this way a circular opening into the 
Water-sac ; lobule often poorly developed; leaf-cells thin-walled 
and without trigones, plane or nearly so, averaging 17 x 12 4 at 
the edge of lobe and 20x 12in the middle and at the base ; 
ocelli I to 4, forming an interrupted median row, scarcely dis- 
Unguishable from the other cells: underleaves distant, 0.04 mm. 
ong, 0.15 mm. wide, with widely spreading filiform divisions, 
€ach consisting of (2 or) 3 cells in a single row, basal portion of 
underleaf broadly trapezoidal, cuneate at the base, the lateral 
Margins continuous with the divisions, radicelliferous region sur- 
rounded by 6 marginal cells: inflorescence dioicous: @? inflores- 
fence borne on a very short branch, innovating on one side with 
