66 BRYOLOGY AND HEPATICOLOGY OF NORTH AMERICA. 



indication of its existence is the bulb at the base of the capsule, 

 which may be the rudiment of that organ. Mr. Schweinitz appears 

 to have detected no caljptra, and my examination of authentic speci- 

 mens of the same species gave a similar result. I was, however, able 

 to verify the presence of the columella pointed out by him in his first 

 notice of the Southern species, but which, in his second and more 

 extended account, is not referred to. With regard to the three spe- 

 cies here given, it can hardly be questioned that N. orbicularis is 

 distinct from the Ohio species ; but that the two plants are equally 

 distinct from each other is not so entirely free from doubt. Still, 

 the specific characters assigned them have thus far proved con- 

 stant. What phases other localities may produce remain to be 

 seen ; for the present (with Nees), " malo peccare in discriminandis 

 quam in confundendis rerum naturae cognitionibus." 



Tab. IV. w3. J^. valvata. — Fig. 1. Plants of the natural size. Fig. 

 2. Portion of the frond, with an involucre and capsule. Figs. 3, 4. Involu- 

 cres and capsules. Fig. 5. A capsule dissected, showing the columella. 

 Fig. 6. Vertical section of an involucre and a portion of the frond, exposing 

 tlie capsule. Fig. 7. A capsule dehiscing by its suture. Fig. 8. Spores. 

 Fig. 9. Upper part of a capsule, showing the line of dehiscence and reticu- 

 lation. Fig. !0. Portion of a frond, showing the imbedded anthers and 

 masses of granules. Fig. 11. Antheridia. Fig. 12. Mass of granules. All 

 magnified. 



B. JV*. orbicularis. — Fig. 1. Plant of the natural size. Figs. 2, 3. A 

 portion of the frond, with fruit. M^. 4. Involucre and capsule. Fig. 5. Cap- 

 sule bursting irregularly. Fig. 6. Spores. The analyses aU magnified. 



Columbus, Ohio, June, 1846. 



