182 
8-10: I; alar cells abruptly enlarged and inflated; leaves of 
primary stems triangular-lanceolate, 0.8 X 0.5 mm., loosely areo- 
late, without chlorophyl: dioicous; male branches stipitate, inner 
perigonial leaves acuminate with broad much twisted apices : 
perichaetium 2.5 mm. long; leaves sheathing at base with squar- 
rose points; the inner oblong-ovate, rather abruptly long subfili- 
form acuminate, entire or slightly denticulate, ecostate. Sporophyte 
1.5-2 cm. high; seta red-brown, very rough; capsule 2-3 by | 
mm., oblong-ovoid, unsymmetric to arcuate, inclined to horizontal ; 
operculum conic-apiculate ; annulus large; segments as long as 
the teeth; cilia one or two, well developed, strongly nodose ; 
spores 134, smooth, maturing in early autumn. 
Type locality European. 
On moist earth in woods; banks of rivers; on stones in 
springs and brooks; subaquatic. Northern U. S. and Canada, 
across the continent south to Virginia ; Pribiloff Islands (C. H. 
Merriam). Not yet reported from California or the extreme 
western United States. Several plants in the Columbia herbarium 
from California which have been referred to this species, are P. 
lamprochryseum. 
ILLUSTRATIONS.—Br. & Sch. E c. ; Husnot, Musc. Gall. pl. 92. 
ExsiccaTi.—Sull. & Lesq. Nace Bor. Am. (Ed. 1-115 
(Ed. 2) 505; Austin, Musc. Appal. 319, 320, 321 and 317 (B. 
rutabulum) ; Macoun, Can. Musc. 288 ; Ren. & Card. Musc. Am. 
Sept. Exsic. 244. 
This species is easily Be ae is by its short acuminate stem 
leaves. 
very interesting form from New Brunswick (Fowler) and 
Bradford, Pa. (Burnett) has secondary stems 8-10 cm. long and 
apparently erect; the leaves of these specimens are much more 
distant than usual. Mr. Burnett states that his plant grew in sev- 
eral inches of water, shaded by grasses and sedges. A rather 
uncommon form has the secondary stems simple and long flagelli- 
13a. BRACHYTHECIUM RIVULARE CATARACTARUM Sauter, Fl. Herz- 
ogth. Salzburg. 3: 60. 1870. 
Floating, dark green to golden green, brown underneath ; 
secondary stems much elongated, simple or sparingly branched ; 
