CHEILOLEJEUNEA POLYANTHA 141 
and differs from it in its autoicous inflorescence and in its leaf-cells, 
which are more convex on the free surface of the lobe and show 
much more conspicuous trigones. 
The type-specimens of Zejeunea Mohrii in the Austin herba- 
rium are apparently referable to Æ. opaca, although sterile and in 
rather poor condition. They do not agree fully with Austin’s de- 
scription because they show bifid underleaves, but this is a charac- 
ter which might have been overlooked. 
E. opaca differs from E. duriuscula in its much larger under- 
leaves, distinctly rounded or cordate at the base, and in the posi- 
tion of its sexual organs, which are borne on short branches rather 
than on leading branches. Occasionally one meets with specimens 
of E. opaca in which the underleaves are smaller than is normal, but 
in such cases a careful search will commonly show underleaves of 
the usual size on some of the axes. 
At one time Spruce * threw doubt on the validity of Æ. opaca, 
suspecting that it was synonymous with Zgjeunea clausa Mont. 
Later he apparently changed his mind, for he distributed speci- 
mens under both of these names in his Hepaticae Spruceanae. 
9. Cheilolejeunea polyantha sp. nov. 
PLATE 19, FIGS. 12-21 
| green or brownish, growing in depressed tufts: stems 
` prostrate, loosely appressed to substratum, 0.1 mm. in diameter, 
copiously and irregularly pinnately branched, sometimes dichot- 
omous: rhizoids scanty: leaves densely imbricated, the lobe 
convex, obliquely spreading, orbicular, 0.4 mm. long, rounded at 
the apex, margin entire or slightly and irregularly angular-sinuate, 
antical margin arching across axis and rounded at base, postical 
margin usually rounded, forming an acute or right angle with 
keel; lobule strongly inflated, ovoid-cylindrical, 0.12 mm. long, 
0.08 mm. wide, keel slightly arched, free margin strongly involute, 
as far as the bluntly pointed apex, then abruptly or obliquely 
truncate to end of keel; cells of lobe slightly convex, with 
somewhat thickened walls and distinct, triangular trigones, aver- 
aging 12 p in diameter at edge of lobe, 21 pin the middle and 
23 4 at the base: underleaves imbricated, sometimes densely so, 
rapidly increasing in size toward a 9 inflorescence, plane, broadly 
orbicular to reniform, 0.25 mm. long, 0.35 wide, bifid about one 
* Hep. Amaz. et And. 245, 1884. 
