the middle, ov simple and ascending to near the apex, yellow ;
basilar cells nari-ower than in IL molle, yellowish, those of thé
basal angles broadly rectangular or hexagonal, orange ; perichætium
erect, sheathing, with few solid sulcate entire leaves: capsule
incurved, cernuous, turgid, oblong, subarcuate, aud constricted
under the oi-ifioe when dry aud empty; operculum
highly convex, obtusely papillate, orange; teeth short; segments
subulate; .annulus large, persistent. — Muse. Frond.
Suec. 63, excl. t. ; Hedw. Sp. Muse. 247, t. 64. IT. molle, Brid.
Bi-yol. Univ. ii. 570, excl. syn. Limnobhim alpestre, Bruch &
Schimp. Bryol. Eur. t. 577.
H ais. North America, according to Austin.
168. H. a rc ticum ,' Sommerf. Tufts loose, rigid, dark olive
green ; stems slender, horny, with few simple branches, naked
and rootless at base: leaves small, open, solid, round-ov.ate,
obtusely pointed, very entire, slightly inflated ou the borders!
plano-concave, subeochleariform; costa distinct, ascending to
below the apex, simple or bifurcate; areolation very narrow,
not dilated at the angles; inner perichætial leaves long-lanceo!
late, costate, scarcely sulcate : capsnle small, suberect or cernuous,
oval, narrowed to a distinct collum, arcuate when dry;
operculum mammiform; segments entire; cilia two, short;
annulus double. —Wahl. El. Lapp. Suppl. 65, t. 2. Limnobium
arcticum, Bruoh & Schimp. Bryol. Eur. t. 578. Stereodon
arcticus. Mitten, Journ. Linn. Soc. viii. 42.
IIab. On rocks along rivulets near Closter, New Jersey (Austin);
Rocky Mountains {Drummond, Lyall).
169. H. obtusifolium, Drumm. Loosely cespitose ; the
branches more numerous, short and simple, thick, turo-id and
suhclavate, or longer and slightly ramulose : ieaves loosely imbricate
all around when dry, half-open when moist, broadly oval,
obtuse, very concave, slightly serrulate ; costa simple, ascending
to near the apex ; areolation very narrow, not enlarged at the
angles : pedicel rough, flexuous, arcuate below the large oval-
oblong pendent or horizontal capsule, which is not constricted
under the orifice when dry; operculum not seen ; peristome as
in IL molle.— Muse. Amer. n. 193. II. arcticum, var., Muell.
Syn. ii. 432. Stereodon obtusifolius. Mitt. 1. e.
Hab. Rivuiets in the Rocky Mountains {Drummond); Britisii Columbia
{lA/nll) ; Mount Dana, California, sterile ( Bolander) ; Oregon, in fruit
{E. Hall), from whose, specimens the diagnosis has been completed.
170. H. m o n tan um , Wils. Ms. Plants small, in wide
soft tumid tufts, reddish-brown within, yeliowish green above ;
stem slender, prostrate, mostly naked, with simple or fastigiately
ramnlose erect branches : leaves variously curved, ofteiier subfalcate
secund, concave or complicate, broadly ovate, lanceolate-
acuminate above, decurrent at base, slightly serrulate all around ;
borders erect or reflexed; costa short and double or none; areolation
narrow, fusiform, larger and oblong at the angles ; inner
perichætial leaves erect, narrowly short-acuminate, sulcate-striate,
serrulate at the aj)ex only; capsule oblong, erect, cernuous;
pedicel slender, subarcuate above ; operculum convex-conical,
mamill.ate ; teeth pale yellow, lamellate inside ; cilia two, as
long as the entire segments, nodose; annulus very broad.—
James, Proc. Philad. Acad. 1855, 447 ; Sulliv. Mosses of U.
States, 72, .and Icon. Muse. 181, t. 113; Sulliv. & Lesq. Muse.
Bor.-Ainer. Exsicc. n. 306.
H a b . Moist rocky banks of rivulets; White Mountains {Oakes, James).
171. H. eu g y rium , Schimp. Tufts appressed, bright yellowish
green, soft ; stems short, branoliing and r.amulose : leaves
close, multiform, those of the stems oblong-lanceolate and short-
acuminate, distichous, those of the branches and branchlets
flexuons-falcate, the upper and lower plano-concave, the i.ateral
subcomplicate, falcate-flexuous, long-lanceolate, diversely curved,
all seriailate ,at the apex only, marked at base by a short j-ellow
line instead of a costa; ceils very narrow, vermicular, those of
the decurrent concave angles abruptly enlarged, rectangular,
with thick dark orange walls ; perichætium long, whitish, its
outer leaves spreading and flexuous from the middle, the inner
erect, sti'ict, long-lanceolate, erose-denticuhate at tlie a]iex, sulcate
: capsule cernuous, ovate-oblong, turgid, yellowish brown ;
operculum highly conve.x-mammiform ; teeth solid, yellow, linear,
deeply articulate above; segments cleft between the articulations
; cilia two or three, as long as the segments, nodose and
granulose ; annulus very broad, triple. — Syn. 639. Limnobium
eugyi'ium, Scliimp. ; Bryol. Eur. t. 579. Amblystegium eugyrium,
Lindb.
H a b . On rocks in mountain brooks, New York and New England.
* * Flowers dioecious.
172. H. o ch ra c eum , Turner, Ms. Widely cespitóse ; tufts
soft, yellowish or ferruginous green, ochraceous within ; stems