A. W. Evans — Hawaiian Sepaticce of the Tribe Jtibuloidece. 393 



being a continuation of the main axis. This condition may be 

 readily distinguished from that in which a flower is really borne on 

 a short lateral branch by the order of the leaves on the apparent axis 

 beyond the flower : in case this is the true axis, the first leaf will be 

 on the side next the flower ; in case it is an innovation, the first leaf 

 will be on the side away from the flower. Very striking examples 

 of each condition may be found in the genus Cololejeunea. 



Subtribe I. FRULLANIE^. 



The Frullanieae include only two genera, Frullania and Juhula, of 

 which only the most important characters will be enumerated here. 



In Frullania, both antical and postical lobes are attached to the 

 axis by very short, almost transverse lines of insertion, the attach- 

 ment in the case of the postical lobe being limited to the base of the 

 stylus. The leaf -lobe, beneath which a branch is situated, is similar 

 to the others in position and is attached to the main axis rather than 

 to the branch. The first underleaf of the branch seems to function 

 as the lobule of this lobe, and their lines of insertion come very close 

 together. This underleaf is similar to other underleaves,* but is 

 often distorted in position ; and sometimes one of its divisions, the 

 one next the lobe, is inflated like an ordinary lobule. Between this 

 underleaf and the lobe, we occasionally find a small leafy structure, 

 now appearing as a minute, subulate process, now as a small, more 

 or less rudimentary sac. According to Leitgebf this interposed body 

 is derived from the first postical segment of the branch, which 

 normally gives rise to the underleaf alone ; it may be looked upon, 

 therefore, as a supplementary part of this underleaf. Properly 

 speaking, innovations are never present in Frullania ; that is, no 

 branches are ever developed just behind the pericliJBtial bracts. It 

 is not unusual, however, to find branching a little farther back from 

 the perianth, and such a branch, which arises in the usual way, may 

 apparently continue the axis, as in the Lejeuneese. The stalk of the 

 capsule is more complicated than in Juhula or the following subtribe, 

 and is usually built up of four concentric layers of cells. 



* According to Spruce (Hep. Amaz. et And. 5), this underleaf is truly the 

 modified lobule, a view which is also expressed by the writer in his own work on 

 the North American FruUanke (Trans. Conn. Acad, x, 3). The explanation 

 just given is that of Leitgeb (Untersuch. liber die Lebermoose, ii, 33), and, being 

 based on embryological studies, is probably more nearly correct. It must be 

 acknowledged, however, that the interposed body (described in the text) some- 

 what obscures Leitgeb's explanation. 



f Unters. iiber die Lebermoose, ii, 35. 1875. 



