Jungennannia Nevicensis, Carr. Trans . Bot.
Soc. Edin., X I I L , p. 464, t. 17, f. 2 ; Carr,
and Pears. Exs. No. 85. Hygrobiella Nevicensis,
Sp ru c e Cephalozia, p. 77.
On moist shelving rocks.— {Plate 2, Jig. 2 7 )
Tufts cushion-like, pale green. Stems i to | inch
long, mostly simple, recurved at the summit, naked
helow. Leaves alternate, remote, round, and
sheathing at the base, shortly bidentate, sinus
narrow, lobes connivent. Texture thin, translucent,
marginal cells subquadrate, others hexagonal.
The tufts resemble in size attenuate forms of
Jung, bicuspidata, but the vertically patent conduplicate
distant leaves, and absence of rootlets,
on all parts, distinguish it from that and other
allied forms. The colour is pale lustreless
yellowish green, stolons stramineous, sometimes
the foliage is tinged with brown. Fructification
unknown.
G e n u s 18 . PLEUROCLADA, Spruce.
Clauce s cent in colour, stem radicellose,
throughout its length almost equa lly foliate,
base not rhizomatose, and not flagelliferous,
subpinnately branched, branches all lateral.
Base of the cauline leaves difformed (uni-
lobed), crowded, leaves v e r y concave, scarcely
c omp l ic a te ; perianth v e r y fleshy, subfloral
innovations none.— On Cephalozia, p. 77.
The Jungermannia albescens of Hooker, which,
by its truly lateral and subpinnate ramification—
without a single postical branch— and by some
other of its characters, including even its bluish
white colour when dry, is perhaps as nearly allied
to Lepidozia reptans and to Antheha as to Cephalozia.
I have therefore separated it as a new
genus, under the name “ Pleuroclada.”—-S'pxnce on
Cephalozia, p. 14.
Pleuroclada albescens, Hook.
S tem creeping, branched ; leaves incumbent,
concave, ovate, emarginate, perichsetial
leaves e v e r yw h e r e imbricate ; st ipules triangular
; perianth terminal on lateral branches,
ovate.
Jungermannia albescens. Hook. Br. Jung.
No. 72, Supp. t. 4 ; Got t . and Rab. Exs . No.
33, 468 ; Co o ke Hep. f. 73. Cephalozia albescens,
Dumort. Rev. Jung. p. 18 ; Lindb. Journ.
Linn. Soc. X I I L , 192. Pleuroclada
albescens. Spruce Cepha loz ia p. 14 ;
Carr, and Pears. Hep. No. 262.
On mountains.
Growing in large loose patches. Stems
I to I inch in length, creeping, waved,
thread-like, branched twice or thrice dichotomously,
and attached to the ground ^
by tufts of radicles. Leaves rather dis-
tant and alternate, very small, nearly hemispherical,
half-embracing at the base, at the apex cut with