149 
mouth of capsule ; segments attached to a wide basal membrane, 
free or adhering to teeth; cilia rudimentary or none. Spores 
minutely roughened. 
Widely distributed in the north temperate zone. 
The generic name Py/aisia was first used by Desvaux in 1814 
to designate a new genus named in honor of De La Pylaie! The 
specimen upon which his genus was founded is stated to be noth- 
ing more than a depauperate form of Hypnum denticulatum L. 
In 1851 Bruch and Schimper took up the name for a new 
genus founded on Hypnum polyanthos Schreb., thus publishing a 
homonym.  DeNotaris in 1869 extended the genus Py/aisia by in- 
cluding Orthothecium of the Bryol. Eur., and in this extended form 
it was degraded by Lindberg in 1879 to a sub-genus of Stercodon 
of Mitten. The name ides nda proposed by Kindberg for two 
species of the genus, viz. : P. velutina and P. subdenticulata, is very 
appropriate, as it will commemorate the name of De La Pylaie. 
Segments of the endostome entirely free from the teeth. 
Operculum conic ; quadrate alar cells few. I. P. polyan 
Operculum short-rostrate ; quadrate alar cells numerous. 2. P. Pei: 
Segments partially or wholly adherent to the teeth. 
Partially adherent; spores 18-24 y. 3. P. intricata. 
Wholly adherent ; spores 25-30 y. 4. P. velutina. 
I, PYLAISIELLA POLYANTHA (Schreb.) Grout, Bull. Torr. Club, 
ag: 220. 19896 
Hypnum polyanthos Schreb. Spicil. Flor. Lips. 97. 1771. 
Pylaisia polyantha Br. & Sch. Bryol. Eur. fasc. 46-47. pi. 
gst. 1951, 
Stereodon polyanthos Mitt. Journ. Linn. Soc. 8: 40. 1865. ` 
Pylaisia heteromalla Br. & Sch. Lond. Journ. Bot. 2: 669. 
1843. 
Hypnum polyanthum pallidıfolium C. Muell. Syn. 2: 337. 
1851. 
Pylaisia Ontariense C. Muell. & Kindb. in Macoun, Cat. Can. 
Fl 6O: 174. 1802 
Gametophyte in glossy yellowish green intricate mats ; stems 
2 to 10 cm. long, rarely longer, creeping, pinnately branchig ; 
branches 0.5 to 1 cm. long, erect or ascending; branch leaves 
somewhat falcate-secund, loosely imbricate when dry, broadly 
-ovate-lanceolate, I-1.3 X 0.4-0.5 mm., more or less long-acumi- 
