BARNES NOETH AMERICAN MOSSES. 341 



acuminate-subulate, strong, densely trabeculate; segments split their 

 whole length; cilia long. Bot. Gaz. 17: 202. 1888. Mixed with Hyp- 

 nura pinnatifidum, California. 



449. Cainptothecium Nuttallii tenue Kindb. Branches longer, fili- 

 form: leaves smaller only at base, hooked denticulate at apex. Mac. Cat. 

 189. Perpendicular rocks: British Columbia. 



450. Brachythecium laetum fall ax R. & C. Branches julaceous, 

 elongated: leaves narrower, longer acuminate, more or less revolute; alar 

 cells soft, hardly incrassate. Hedwigia 32: 257. 1893. Calumet River, 

 Ind. 



451. Brachythecium laetum Roellii Ren. & Card. Stems depressed, 

 pinnate; branches julaceous, short, obtuse: leaves densely imbricate, 

 broader, concave, shorter acuminate: alar cells as in preceding variety. 

 1. c. Calumet River, near Hobart, Ind. 



452. Brachythecium laetnm pseudo-acuminatum Ren. & Card. Deli- 

 cate, habit B. acuminatum: leaves deeply plicate, basal angles excavate; 

 alar cells less numerous but distinct. 1. c. Calumet River, near Hobart, 

 Ind. 



453. Brachythecium digastrum C. M. & Kindb. Tufts laxly cohering, 

 olive-green, not shining: stem rigid, sub-pinnate or irregularly branching, 

 radiculose below; branches sub-julaceous, obtusate: stem leaves when dry 

 loosely appressed or sub-imbricate, crowded, patent or sub-secund when 

 moist, decurrent, not auricled, plicate, biventrose, ovate, short acuminate 

 with flexuous acumen, or when dry serpentine-corrugate; borders more or 

 less recurved but not reflexed, sub-entire or faintly denticulate above; lower 

 basal cells wide and sub-rhombic, alar rather quadrate-rectangular and not 

 very distinct, upper conflate small very chlorophyllose, inner median sub- 

 linear, others oblong-lanceolate; costa thick and sub-flexuous, long, vanish- 

 ing near acumen; branch leaves ovate oblong, more distinctly revolute at 

 borders, denticulate at acumen, narrower areolate: capsule asymmetric, 

 sub-cylindric, curved; lid long conic; seta smooth; teeth of peristome conic 

 connivent when moist, cilia nodulose, not appendiculate: monoicous. 

 Mac. Cat. 190. Ottawa, Ont.; New Brunswick. 



454. Brachythecium Fitzgeraldi C. Mull. Dioicous: tufts low, pulvi- 

 nate, broad, yellow, loosely interwoven: stem with branches short, more or 

 less parallel, slender, round-julaceous; branchlets very short, rather spread- 

 ing, single: stem leaves closely appressed, when moist scarcely spreading 

 with cordate base semicircularly impressed, rather broad ovate, short acu- 

 minate; more or less ventricose-concave on both sides of the narrow vanish- 

 ing deeply canaliculate green costa; margin nearly plane, everywhere 

 slightly denticulate; cells very narrow, long, pale yellow; alar cells many, 

 small, hexagonal: fruit unknown. Flora 70: 224. 1887. Florida. 



