173 
rower leaves and a more dirty green color; var. pseudo-acumina- 
tum is a dwarfed and more caespitose plant, but differs in no es- 
sential particular from the ordinary form of B. oxycladon except, 
perhaps, in the more slender pointed branch leaves. Var. Roellit 
is not at all like B. /aetum, having short julaceous branches and 
ovate to ovate-lanceolate leaves of about 77 the size of the leaves of 
B. laetum. All of these varieties were sterile and the species in 
the salebrosum group of Brachythecium are too closely related to 
make valid varieties from sterile specimens. 
Renauld & Cardot's 104 differs in no essential respect from the : 
ordinary B. oxycladon but as compared with the type of B. dzventro- 
sum it is larger and stouter; leaves broader and less slender 
pointed, basal areolation that of B. orycladon. I am unable to 
agree with the opinion expressed by M. Cardot in Hedwigia 35: 
municated by Lesquereux could not have been this species or he 
would not have confused it with B. /aeztum. B. biventrosum is very 
closely related to B. acuminatum as is indicated by the erect cap- 
sule, imperfect peristome and general appearance. Specimens of 
B. digastrum of the type collection are very distinct from 2. oxy- 
cladon and are most closely allied to the plumosum group as is in- 
dicated by. the leaf characters and general appearance. 
6a. BRACHYTHECIUM OXYCLADON DENTATUM (L. & J.). 
Hypnum laetum dentatum L. & J. Mosses of North America 
335. 1854. 
Brachythecium Sullivanti Br. & Sch. Bryol. Eur. fasc. 
$2694: 21. 1853. 
Gametophyte often submerged and dirty brownish green below ; 
stems and branches slender, stem leaves broader and shorter, acute 
to acuminate, serrulate; branch leaves shorter pointed and more 
strongly serrate, more obest. areolate at base. Seta 3-3.5 cm." 
long, very slightly roughened at base ; operculum short-rostrate ; 
apparently growing in wet places and rocks on earth. 
In woods near, and on the banks of the Hackensack River, 
Closter, N. J. (Austin) ; on ground in ravines, Louisiana (Langlois) ; 
banks of a creek, Saline Co., Missouri (Rev. C. H. Demetrio) ; 
swamp, Monkton, Vt. (C. G. Pringle). 
Exsiccati.—Sull. Musc. Allegh. 43, in part only. 
