GYROTHYRA 89 
tuse or rarely acute; leaf-cells oval or round-hexagonal, the 
median 16-28 и, the marginal usually a little smaller, all with 
large trigones: dioicous: antheridia in groups of 2-6, on stalks 
equaling their vertical diameter or sometimes twice as long, the 
bracts often with slightly revolute margins: 9 bracts 2-4 pairs, 
gradually 2 or 3 times larger than the leaves, very rarely sub- 
marginate, the inmost pair highly connate, exserted or immersed, 
one or two of the exterior pairs sometimes connate at base, lobes 
similar to those of leaves, median cells 25-34 и: perianth some- 
what shorter than bracts, 4—6-lobed: capsule yellowish-brown, 
oblong-globose, .54-.7 mm. in length; seta 2-10 mm. long. 
On a moist roadside bank near Lake San Andreas, San Mateo 
Co., Apr. 20, 1895—in company with the foregoing species. 
18. GYROTHYRA M. A. Howe, Bull. Torr. Bot. Club, 24: 201. 
1897. 
Stem creeping, foliose, subsimple or somewhat sparingly 
branching, radiculose. Leaves succubous, entire, alternate ; under- 
leaves present, free, bifid, segments narrowly lanceolate or subu- 
late; walls of the leaf-cells with triangular thickenings at the 
angles. Antheridia short-stalked, in the axils of smaller saccate 
leaves, forming short median or, at first, terminal spikes. C bracts 
2-4 pairs (commonly 3 pairs), Perianth terminal, confluent for 
half its length or more with the bases of the bracts, the greater part 
of the calyptra, and the tissues of the stem, to form a thick-walled 
tube (perigynium), with a small bulbous or saccate base ; am 
gynium erect or ascending, making, at maturity, nearly a rig t 
angle with the stem. Capsule cylindrical, long-exserted, wwe 
spirally by four very long and slender valves; capsule-valves о 
two layers of cells, the walls wholly destitute of spiral, semian- 
nular, or other local thickenings. laters free, bispiral, acute x 
bluntly pointed ; spores minutely papillate. « Involucellum " о 
the sporogonium foot well developed. 
: ^L 202 
І. GvyRorHYRA UNDERWOODIANA M. A. Howe, L с. 202. pl. 302, 
303. , 
Plants rather large, 1-2 cm. long, 2-4 mm. wide, дон 
compact light green tufts: stems creeping, thick, often mechs 
flattened dorso-ventrally, .5—.65 mm. in Hameet, spem s! са! 
Wide in cross section, very densely radiculose, slightly пр: ws 
apex, subsimple or with a few irregularly disposed еи = ain 
in female plant innovating from near base di sci mar: le бше 
long, nearly colorless or of a dilute yellowish-brown hue, < 
