WILLIAMS: THE GENUS DESMATODON Oto. 
5. DESMATODON OBTUSIFOLIUS (Schwaegr.) Jur. Laubm. Oéesterr. 
Vie 196.2082" 
Barbula obtusifolia Schwaegr. Suppl. 1: 129. 1811. 
Desmatodon oblongifolius Hook. in Drummond, Musci Am. 114. 
1828 (nomen nudum). 
Tortula obtusifolia Schleich.; Broth. in E. & P. Nat. Pfl. 1°: 430. 
1902. 
Desmatodon arenaceus Sull. in Gray, Man. ed. 2,628. 1856. 
Desmatodon ohioense Schimp. Syn. 159. 1860. 
Desmatodon subtorquescens C. Miill. & Kindb.; Macoun, Cat. Can. 
Pl.6:48. 1892 (apparently). | 
Didymodon arenaceus Kindb. Eur. & N. Am. Bryin. 277. 1897. 
erect, 2 mm. long, with stomata in one row in the short, scarcely 
distinct neck; peristome variable, pale to reddish brown, finely 
papillose throughout, the basilar membrane extending usually a 
little above the rim of the capsule and either bearing slightly ob- 
lique teeth once or twice divided into slender forks of unequal 
