— 12 — 
apex of stems and branches, fragile, often ragged or broken off, stem leaves 
ovate to oblong-lanceolate, obtuse or short acuminate, entire 3-3 5 by 0.9- 
1.2 mm., branch leaves narrower, 2. 1-3.5 by .6-85 mm. ; alar cells subquad- 
rate or oblong, not strongly differentiated, others linear, subflexuous, upper 
sbprter, all chlorophyllose. Other characters unknown. 
Seems to be related to F Novae- Angliae Sulliv., but readily distin- 
guished'from this species by the leaves (chiefly the branch leaves) which are 
narrower, longer acuminate, entire at apex, and by the much smaller and 
less distinct alar cells. It belongs to the section Helerophyllae . 
In the Minnesota River Channel, at Granite Falls (July 12, 1901). 
Amblystegium brachyphyllum Card & Ther. 
-^■Related to A. ripariuni from which it differs in its shorter ovate-lance- 
olate leaves, 1 -,6-1.7 by 0.7 mm., short acuminate, apex obtuse or subobtuse; 
costa strong, broader at base, 50-80/4 wide, extending 2/3 or 3/4 the length 
of leaf; median cells linear, 70-90/4. Fruit unknown. 
By the blunt or subobtuse acumen this moss resembles A. vacillans 
Sulliv., but it has much shorter and broader leaves. From A. brevipes 
Card. & Ther., it is well distinguished by the larger size, the blunt acumen, 
the longer and narrower cells, and the stronger costa. The polymorphous 
A. ripariuni constitutes a vast group of forms, some of which are constant 
enough and are sufficiently characterized to be considered as secondary or 
tertiary species; such are A. Kochii B. & S., A. vacillans Sulliv., A. 
brachyphyllum and A. brevipes Card. & Ther., A. floridanum Ren. & 
Card., and probably A. argillicola Lindb. 
Granite Falls (July 15, 1901), 
Amblystegium brevipes Card. & Ther. 
In the A. ripariuni section of the genus ; stems slender, creeping, 
branches short, leaves erect-open, about 1.2 by 0.6 mm., broadly ovate,, 
short-acuminate, entire ; costa narrow, 30/4 wide at base, vanishing beyond 
the middle, often extending 273-3/4 the length of the leaf; areolation lax, 
basal cells rectangular, some quadrate, median subhexagonal, 55-70 by 
12-15/4, upper shorter and broader; perichaetial leaves broadly ovate, sud- 
denly narrowed into a slender acumen, often irregularly denticulate at base 
of acumen; costa extends beyond the middle; seta short, capsule oblong- 
arcuate, constricted under the mouth when dry: operculum conic. 
This species differs from small forms of A. riparium by the shortly 
acuminate leaves, the looser areolation, the shape of the perichaetial leaves, 
and the short pedicel. A species from the Caucasus, A. argillicola Lindb.. 
of which we know only the description published by Dr. V. F. Brotberus in 
his valuable paper, “ Enumeratio Muscorum Caucasi,” Seems to be nearer tO' 
this species but still stands distinct from it by its leaves which are minutely ► 
denticulate from almost the base, its longer costa vanishing below the apex, 
and its narrower perichaetial bracts, with a less distinct nerve. 
Near Montevideo (June 15, 1901); Hartford (June 27, 1901). 
