BULLETIN 
TORREY BOTANICAL CLUB. 
Vol. 23. Lancaster, Pa., June 30, 1890. No. 6. 
A preliminary Revision of the North American Isotheciaceae. 
By A. J. Grout. 
During the past winter a critical study of this family of mosses 
has been made at the Herbarium of Columbia University. Wish- 
ing to obtain more material illustrating the distribution of the 
species, a brief summary is here presented, giving the distribution, 
so far as can be determined, from material at hand. Persons 
having specimens from outside the range here indicated will con- 
fer a great favor by sending them to me at the Herbarium of 
Columbia University. If duplicates can also be sent, a suitable 
return will be made for them. I am already greatly indebted to 
several persons for aid in my work, for which acknowledgments 
will be made in the final publication. 
ISOTHECIACEAE Spruce, Ann, and Mag. Nat. Hist. (II.) 3: 
285. 1849. 
Gametophyte generally large, never minute. Primary stems 
creeping, radiculose. Paraphyllia lacking (except in Cimacium). 
Leaves smooth, often plicate or concave; median leaf-cells linear, _ 
alar cells quadrate (except in Holmgrenia). 
Sporophyte. Seta smooth, twisted. Calyptra cucullate. Oper- 
culum conic to conic-rostrate. Columella persistent. Capsule 
erect, straight, not conspicuously contracted under the mouth 
when dry. Peristome double, well developed; teeth lanceolate, __ 
articulate. Segments of endostome linear to lanceolate, attached 
