AND HEPATICOLOGY OF NORTH AMERICA. 69 



terminales. Folia perigonialia 2, basi ventricoso-vaginantia, parte 

 superiore condiiplicaturae eroso-truncata, c<eterum caulinis similia; 

 antheridia3-4, filamento brevissimo sufifulta, paraphysibus nullis : 

 perichajtialia 2, caulinis superioribus conformia sed longiora. Cap- 

 sula erecta, symmetrica, ovalis, inferne attenuata, siccitate sub ore 

 dilatato constricta : pedicellus 1 lineam longus, e basi geniculata 

 flexuoso-ascendens, siccus sinistrorsum tortus: peristomii dentes 

 erecto-incurvati, rubelli, apice ultra medium fissi, dense articulati, 

 cruribus insqualibus subulatis granuloso-scabris : operculum conico- 

 rostratum ; rostro recto, aut vix curvato, dimidiam capsulje partem 

 longitudine jequante : calyptra solum operculum obtegens, conico- 

 subulata, uno latere profunde fissa: sporae majuscute diametro 

 sequantes dentis basi dimidiam latitudinem. 



This species grows on stones in the bed of desiccated rivulets, in 

 shaded places, near Columbus, Ohio ; it fruits in July and August. 

 Besides other marks of less importance, the dicecity of this moss 

 readily distinguishes it from F. incurvus, Br. ^ ScL, small forms 

 of which it much resembles. The character in the foregoing de- 

 scription, drawn from the relative length of the diameter of a 

 spore and the breadth of a tooth of the peristome near the base, 

 may be made available in many cases for distinguishing species. 

 In the present species and its nearest ally, F. incurvus, this char- 

 acter is efficient, since in the latter a spore equals one third the 

 breadth of the peristomal tooth. In the F. obtusifolius, Wils., 

 the spores are unusually large, one being more than sufficient to 

 cover the breadth of a tooth. 



Tab. II. Jl.—Fig. 1. Plants of the natural size. Figs. 2, 4. Capsules. 

 Fig. 3. Calyptra. Fig. 5. Female plant. Fig. 6. Male plant. Fig. 7. An- 

 tlieridia. Fig. 8. A leaf. Figs. 9, 10. Portions of a leaf. Fig. 11. Por- 

 tion of the peristome. Fig. 12. .Spores. All except Fig. 1 more or less 

 magnified. 



