348 EVANS [ 2 94] 



dish : stems sparingly branched, canaliculate when dry along antical 

 surface (between the rows of leaves), convex postically, on sterile 

 plants of about the same width throughout, on sexual plants broaden- 

 ing clavately upward : leaves transversely inserted, densely imbricated, 

 strongly concave and appressed symmetrically, broadly ovate or oval 

 (when flattened), equally bilobed i-^ the length of the leaf with a 

 very narrow sinus, broadening upward, and rounded or very obtuse 

 lobes, sometimes overlapping slightly at the base; margins distinctly 

 crenulate from projecting cells except in basal portions of leaf ; green 

 tissue of leaf limited to a patch extending from the base to, or consid- 

 erably beyond, the middle, surrounded by a distinct hyaline border, 

 except sometimes close to the antical base; marginal cells in crenulate 

 portion of leaf with rather uniformly thickened walls, remaining hy- 

 aline cells with large and often confluent trigones, green cells with 

 thin walls and distinct but sometimes very small trigones; cuticle 

 densely and minutely verruculose, particularly in the hyaline portions 

 of leaf : 9 inflorescence borne on a principal branch, outer bracts in 

 three or four pairs, closely imbricated, similar in shape to the leaves, 

 but larger, squarrose at the apex and more or less reflexed on margins 

 of lobes; inner bracts much smaller and more delicate in texture, ir- 

 regular in shape and variously lobed or cleft with subacute divisions, 

 slightly crenulate on the margins from projecting cells and persistent 

 papilla?; archegonia numerous (up to 10 or 12) : $ inflorescence on a 

 principal branch ; bracts in several pairs, closely imbricated, similar 

 to the leaves in shape but more delicate in texture, subsquarrose at 

 apex and often reflexed along margins of lobes; antheridia two in 

 each axil, one on a much longer stalk than the other: capsule dark 

 brown, globose, borne on a short stalk extending slightly beyond the 

 cluster of 9 bracts, capsule-wall composed of two layers of cells; 

 thickenings in the partition-walls of outer layer very conspicuous, dark 

 brown, rounded, extending -| ^ across cell-cavity, more or less conflu- 

 ent at the base ; similar thickenings of inner layer smaller and less dis- 

 tinct but deeply pigmented, half-ring thickenings of same layer much 

 paler, often indistinct or wanting; spores brown, somewhat angular, 

 with a thick, very minutely verruculose wall ; elaters brown, mostly 

 bispiral. 



Leaves o.S x 0.75 mm., leaf-cells at edge of leaf 14 fj. in diameter, 

 in the middle 17 //., at the base 30 x 22 /*, outer 9 bracts i.i X i.i 

 mm., $ bracts 0.85 x 0.85 rnm., spores 13 /* in diameter, elaters 

 40-70 \i long, 7 /-* wide. 



Orca (T. 1512, in part, 9 specimens with capsules). New to 

 Alaska. 



