171 
that this species is distinct from the European B. Mildeanum Sch. 
The aspect of the plant is different in that it has loosely foliate and , 
rather flaccid branches, while B. Mildeanum has more robust, 
densely foliate, turgid branches. The leaves are long, slender- 
pointed, more like B. glarcosum than B. Mildeanum. Sullivant’s 
figure resembles B. Mildeanum more closely than B. acutum. 
Mitten’s figure represents the leaf much more accurately. Aus- 
tin's Musc. Appal. 316, is, however, more like B. Mildeanum and 
Sullivant's figure and may prove to be distinct. There seems to 
be a complete series of intergradations between this species and 
B. salebrosum. The gradually tapering stem leaves which are sel- 
dom plicate and the more slender-pointed and less serrate branch 
leaves are the characters most easily recognized. 
6. BRACHYTHECIUM OXYCLADON (Brid.) Jaeg. & Sauer. St. Gall. 
Nat. Gesell. 1877-1878 : 323. 
Hypnum oxycladon Brid. Musc. Recent. Suppl. 2: 123. 1812. 
Hypnum laetum Brid. Bryol. Univ. 2: 479. 1827. 
Hypnum luteolum C. Muell. Syn. 2: 357. 1851. 
Brachythecium laetum Br. & Sch. Bryol. Eur. fasc. 52—54. 
pl. 554. 1853. | 
Brachythectum spurio-acuminatum C. Muell. & Kindb. in Ma- 
coun, Cat. Can. Pl. 191. 1892. 
— Gametophyte in wide glossy yellow-green intricate mats ; stems 
prostrate, irregularly divided, pinnately branching ; branches un- 
equal, 0.5-2.5 cm. long, attenuate at ends; upper branch leaves 
erect-open, ovate-lanceolate, slightly decurrent, 1.5-2 X 0.45-0.8 
mm., acute to slenderly acuminate, apex often slightly twisted, 
serrulate nearly all around, concave, plicate, upper margins often 
slightly recurved; costa extending beyond the middle ; median 
cells narrowly linear, 10: 1 ; areolation gradually becoming shorter 
and broader toward the base; alar cells quadrate; stem leaves 
larger, 272.5 X 0.9-1.2 mm., often nearly entire, more deeply 
plicate : dioicous or rarely monoicous ; male branches gemmiform, 
borne on the stem; antheridia oblong to obovoid; paraphyses 
numerous, stout, longer than antheridia; inner perigonial leaves 
ovate to oblong-ovate, acuminate, ecostate, loosely areolate : peri- 
chaetium 2-2.5 mm. long; leaves sheathing at base; the inner 
