Paris of Fructification in Mosses. 319 



firmly colieiing with the teeth by the inner side of their apices. 

 It docs not therefore properly belong to the operculum, though 

 in some cases it may adhere to it, as does the analogous process 

 of the columella in Dazcsonia and in several other Mosses. 

 The affinity of Dausonia to Biixbaumia is certainly less strict 

 than to PolijfricJinm, and rests chiefly on the similarity of the 

 figure of the capsule, and in the central process of the colu- 

 mella, which is still more evident in Buxbaumia, where it forms 

 part of the Linnean generic character, though unaccountably 

 overlooked by Schmidel in his masterly dissertation ; bul, if 1 

 mistake not, actually represented by him [in fig. 14, b, /. c], 

 and confounded with the peristomium, which in this case, I 

 suppose, had adhered to the operculum, as 1 have repeatedly 

 found it to do, and thus escaped his notice. Hedwig consi- 

 ders the plaited membrane which constitutes the peristomium 

 of Buxbaumia, as derived from the inner membrane of the 

 capsule, and quotes the figure just mentioned of Sclnnidel in 

 proof of this origin. In both species, however, I find it arising 

 from the exterior membrane, though considerably within its 

 margin, which in Buxbaumia aplujUa is said by Hedwig to be 

 divided into teeth, — an appearance I could not observe in the 

 few ripe capsules I have dissected. In other respects, the two 

 species seem essentially to agree, and therefore ought not to 

 be separated, as Ehrhart and some late writers have done. 

 The generic character comprehending both, I would propose 

 to alter in the following manner. 



BUXBAUMIA. 



Capsula obliqua, hinc convexior, v. gibba. 



Peristomium intra raarginem, quandoque dentatum, membranae 

 exterioris ortum, tubulosum, plicatum, apice apertum. 



2t2 LEPTO- 



