AND HEPATICOLOGY OF NORTH AMERICA. (59) 5 



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

 superiore conduplicaturas eroso-truncata, caeterum caulinis similia ; 

 antheridia 3-4, filamento brevissimo suffiilta, paraphysibus nullis : 

 perichaetialia 2, caulinis superioribus conformia sed longiora. Cap- 

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

 dilatato constricta : pedicellus 1 lineara longus, e basi geniculata 

 flexuoso-ascendens, siccus sinistrorsum tortus : peristomii denies 

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

 cruribus inaequalibus subulatis granuloso-scabris : operculum conico- 

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

 longitudine sequante : calyptra solum operculum obtegens, conico- 

 subulata, uno latere profunde fissa : sporae majusculae diametro 

 aequantes 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 dioecity of this moss 

 readily distinguishes it from F. incurvus, Br. & Sch., 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- 

 theridia. 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. 



