229 
of the genus, viz.: P. velutna and P. subdenticulata, is very appro- 
priate, as it will preserve the name of De La Pylaie. 
Segments of the endostome entirely free from the teeth. 
Operculum conic; cilia present, rudimentary. 1. 2. polyantha. 
Operculum short, rostrate ; cilia lacking, 2. £. subdenticulata. 
Segments partially or wholly adherent to the teeth: 
Partially adherent; spores 18-24 3. LP. intricata, 
Wholly adherent; spores 25-30 yu. 4. £. velutina. 
I, PYLAISIELLA POLYANTHA (Schreb.). 
flypnum polyanthos Schreb. Spicil. Flor. Lips. 97. 1771. 
Pylatsia polyantha Br. & Sch. Bry. Eur. fasc. 46 and 47. pl. 455. 
1851, 
Stereodon polyanthos Mitt. Journ. Linn. Soc. 8: 40. 1865. 
Pylaisia heteromalla Br. & Sch. Lond. Jour. Bot. 2: 669. 1843. 
fypnum polyanthum palhdifolium C. Muell. Syn. 2: 337. 1851. 
Pylaisia Ontariense C. Muell. & Kindb. in Macoun, Cat. Can. 
Pl.6: 174. 1892. 
Canada and northwestern United States (Macoun); Kakabeka 
Falls, Ont. (Mrs. Britton) ; Saskatchewan and Rocky Mountains 
(Bourgeau); Santa Fé (Fendler); White Mountains ( James) ; Mon- 
tana (R.S. Williams); Pike’s Peak, Colo. (S. L. Clarke) ; Minnesota 
(F. F. Wood). Apparently widely distributed in Canada and 
along the northern border of the United States in mountainous 
regions, but rather infrequent and local. 
The typical American form of this species is quite variable in 
leaf characters, even on the same plant, but it differs constantly 
from European specimens in that the leaves are shorter, more ab- 
ruptly acuminate and more broadly ovate-lanceolate. The length 
of the leaf of the European form averages 1.5 mm.; that of the 
American 1 mm., though I have found one plant whose leaves 
measured 1.4mm. ‘The length of the acumination of the peri- 
chaetial leaves is also very variable. It may be that our forms of 
this and the next species are but two varieties of the European Pag 
polyantha. The American polyantha answers very closely to the 
description of P. polyantha brevifolia Lindb. & Aruell, Musc. Asiae- 
bor. 152. 1890. I have seen the type specimens of P. /eteromalla 
from Schimper’s herbarium and not only are they P. polyantha,but —— 
