Evans: HEPATICAE OF PUERTO RICO 273 
or paroicous: 2 inflorescence borne on a leading branch with one 
or two innovations; bracts complicate, unequally bifid, the lobe as 
in the leaves, the lobule plane; perianth obovoid, terete or five- 
keeled in the upper part, rounded at the apex and abruptly con- 
tracted at the apex into a short (sometimes obsolete) beak, surface 
often roughened from projecting cells. (Name from afavys, invis- 
ible, and Lejeunea, in allusion to the inconspicuous character of 
the species.) 
Type species, Aphanolejeunea microscopica (Tayl.) comb. nov. 
Jungermannia microscopica Tayl. in Mackay, Fl. Hibern. 2: 59. 
1836. Lejeunea microscopica Tayl. in G. L. & N. Syn. Hep. 345. 
1845. Lejeunea (Colo-Lejeunea) microscopica Spruce, Hep. Amaz. 
et And. 293. 1884. Cololejeunea microscopica Schiffn. in Engler 
& Prantl, Nat. Pflanzenfam. 13: 122. 1895. 
Three species that are apparently referable to A phanolejeunea 
have been reported from Puerto Rico, namely: Lejeunea sicaefolia 
Gottsche, L. Sintenisii Steph., and L. heterophylla Goebel. The 
first two are cited by Stephani,* the third by Goebel.j Un- 
fortunately L. Sintenisii and L. heterophylla are known to the 
writer from descriptions and figures only, and it seems necessary 
at the present time to withhold judgment in regard to them. L. 
sicaefolia, however, has been collected in some quantity, and two 
other species, apparently undescribed, are also present in the 
material examined. 
Aphanolejeunea exigua sp. nov. 
Pale green, scattered or growing in thin mats, often mixed 
with other hepatics: stems zigzag, 0.025 mm. in diameter, usually 
simple except for the subfloral innovations: leaves distant, ob- 
liquely spreading, subsquarrose, the lobe ovate, concave, 0.2 mm 
long, 0.1 mm. wide, apex mostly subacute and tipped with a single 
cell, rarely blunt and tipped with two cells side by side, antical 
margin spreading widely from the very base, slightly curved, 
postical margin beyond the keel very short, straight or slightly 
curved, margin crenulate from projecting cells; lobule ovate, 0.15 
mm. long, 0.1 mm. wide, inflated throughout but more strongly 
so in the basal portion, free margin involute to beyond the apex, 
the latter tipped with a more or less curved cell or apical tooth, 
proximal tooth slightly projecting, also consisting of a single cell, 
* Hedwigia 27: 290, 291. pl. 12. f. 21-24. pl. 13. f. 27. 1888. 
+ Pflanzenbiol. Schild. 1: 178, 179. f. 79. 1889. 
