MICROLEJEUNEA RUTHII 161 
Lejeunea, while Stephani * considered it a Zu-Lejeunea. Both of 
these opinions were afterwards reversed, Spruce f placing it in 
Eu-Lejeunea and Stephani t in Micro-Lejeunea. As a matter of 
fact it is intermediate between the two genera, and it is here placed 
in Microlejeunea because it seems to have more in common with 
our other species of this genus that it does with our species os 
Lejeunea proper. Its differential characters will be discussed in ۰ 
connection with the remaining species of Microlejeunea. 
17. Microlejeunea Ruthii sp. nov. 
PLATE 21, Fics. 11-19 
Pale or dull green, scattered among other hepatics or loosely 
depressed-caespitose: stems prostrate, 0.04 mm. in diameter, 
sparingly and irregularly branched, the branches widely spread- 
ing : rhizoids scanty : leaves distant to loosely imbricated, the lobe . 
obliquely spreading to suberect, ovate or broadly ovate, 0.35 mm. 
long, 0.2 m. wide, rounded at the apex, margin subentire 
or slightly angular-sinuate, antical margin extending partially 
across axis, almost straight or slightly rounded at base, often a 
little contracted just above insertion, postical margin almost straight, 
forming a continuous line or sometimes on robust axes a very 
obtuse angle with keel ; lobule about half as long as lobe, strongly 
inflated, ovoid, 0.17 mm. long, 0.13 mm. wide, keel more or less 
arched, free margin curved, strongly involute to apex, then passing 
by an oblique and lunulate sinus to end of keel, apex tipped with a 
single projecting, sometimes outwardly curved cell ; cells of lobe 
plane or slightly convex, walls somewhat thickened with indistinct 
trigones and occasional intermediate thickenings, averaging 12 ^ in 
diameter at the edge of lobe, 18 x in the middle and at the base: 
underleaves distant, orbicular, o. 14 mm. long, narrowed toward base 
and neither rounded nor decurrent, bifid to about the middle with 
broad, suberect, triangular lobes and obtuse sinus, lobes subacute 
or acute, ending in a single cell or in a row of two cells, or robust 
stems usually four cells long and four cells wide at base, margin 
entire or subcrenulate from projecting cells, lateral margins 
rounded, never toothed: inflorescence dioicous: ¥ inflorescence 
borne on a leading branch, innovating on one side, the innovation 
usually long and sterile ; bracts complicate, deeply and unequally 
bifid, the lobe obliquely spreading, ovate to oblong, o.5 mm. long, 
* Hedwigia, 29: 84. 1890 
T Jour. Linn. Soc, Bot. 30: 
t Bot. Gazette, 17: 171. 1 
348. 1894. 
892. 
