70 American Midland Naturalist Monograph No. 6 



F Leaves broadly oblong-lanceolate: capsules usually more or less curved: plants 



usually more than 2 mm 2. F. bryoides var. incurvus 



F. Leaves narrowly oblong-lanceolate: capsules usually erect: plants often less than 2 



mm high 4. F. minutulus 



G. Leaves without ar marginal band of several rows of somewhat paler cells, the outer 



row sometimes paler ^ I 



G. Leaves with a marginal band of several rows of paler incrassate cells H 



H. Upper median leaf-cells rather obscure, about .006-.010 x .006-.014 mm; border 



distinct 6. F. cristatus 



H. Upper median leaf-cells distinct, about .012-.016 x .015-.025 mm; border not 



very distinct 7. F. adiantoides 



I. Costa excurrent into the apiculus 8. F. taxifolius 



I. Costa not quite reaching apex J 



J. Leaves often apiculate: seta terminal: leaf-cells .010-.016 x .014-. 020 mm 



9. F. osmundioides 



J. Leaves more or less rounded at apex: seta lateral in basal half of stem: leaf-cells 



about .007-.011 mm 10. F. subbasilaris 



1. FiSSlDENS HYALINUS Hooker and Wilson 



Plate LXI 



Gregarious, pale green, minute, 2-4 mm high: stem usually simple, erect; 

 leaves in 3-5 pairs, soft, the upper much larger, lance-oblong, acute, non-costate, 

 margined by a single row of narrow elongate cells, the sheath hardly reaching 

 the middle of the leaf, margin entire; cells large, about .030-.045 x .060-. ICO 

 mm, thin-walled, irregularly elongate-hexagonal, hyaline: seta terminal, 1-2 mm 

 long, erect smooth; capsule oblong, erect, thin-walled; teeth closely articulate, 

 red, cleft to the middle; operculum rostrate; calyptra cylindric-conic and cov- 

 ering the rostrum only of the operculum; spores .014-.020 mm. 



The original station of this rare moss was "moist, rocky ledges, Bank Lick, 

 on Cassidy's farm, near Cincinnati, Ohio," where it was first collected by T. G. 

 Lea, in 1839. This station has since been lost, but the moss has been found 

 elsewhere in Ohio: on ground in deep ravines near Plainesville, — H. C. 

 Beardslee, and later in Pennsylvania, as follows: 



Washington Co.: On clay banks with Fissidens taxifolius on banks in ravines near 

 Washington, September and October, 1892, 1894, and 1898. Linn and Simonton. Bank 

 in shaded ravine near Monongahela Lock No. 4, Linn & Simonton. Sept. 6, 1895 

 (figured). 



2. Fissidens bryoides [Linnaeus] Hedwig 



(Hypnum bryoides Linnaeus) 

 Plate XIV 

 In loose tufts or densely gregarious, rather dark green: stems ascending or 

 erect, 5-15 mm high; leaves numerous, ascending, or the apical erect, oblong- 

 lingulate, usually abruptly and somewhat obliquely acuminate, the sheath 

 reaching about half way to the apex, the dorsal lamina gradually becoming 

 very narrow at base, the border strong and reaching the apex, where it becomes 

 confluent with the costa, margin entire or sometimes faintly denticulate at 

 apex; costa strong; leaf-cells rounded-hexagonal, somewhat incrassate, some- 

 what smaller at the apex of the sheath, becoming rectangular at the base, the 

 border consisting of two or three rows of linear-prosenchymatous incrassate 



