Tlic Genus Riccardia in Chile. 163 



The male branches sometimes grow out directly from a main 

 axis but they occur much more frequently in subopposite pairs at 

 the base of a photosynthetic branch-system, where they represent 

 the first two secondary branches. Sometimes there is only one 

 male branch at the base of the system ; sometimes one or both sides 

 will show two such branches. The inflorescence (Fig. 7, H) 

 occupies nearly the whole of the branch, measuring usually 0.7-1 

 mm. in length and 0.3-0.45 mm. in width, and so far no prolifera- 

 tions have been observed. The narrow wings, one or two cells 

 wide, are sometimes erect but usually connivent, partially covering 

 over the upper surface of the inflorescence, and their margins are 

 irregularly crenulate from projecting cells. The antheridia are 

 usually from six to ten ; in one case fourteen were observed, and 

 Stephani states that there are sometimes as many as twenty. The 

 openings of the antheridial chambers are separated by three or 

 four rows of cells, those immediately surrounding the opening 

 sometimes forming a slightly elevated, complete or incomplete ring. 



The female branches are exceedingly short and are similar in 

 position to the male l)ranches. In one case a short and simple pro- 

 liferation could be demonstrated. The most conspicuous feature 

 of the branch (Fig. 7, I) is a lobe-like outgrowth on the outside, 

 lying in the same plane as the Ijranch-system and crenulate, 

 denticulate or short-ciliate along the edge. Apparently in the axil 

 of this outgrowth a small cluster of archegonia, directed forward, 

 is situated and this is protected by a double series of cilia or short- 

 ciliate lobes, representing the wings of the branch and constituting 

 the involucre of the inflorescence. These cilia or lobes are mostly 

 two to five cells long. Stephani describes the "calyptra" as very 

 large, thick and smooth, with a large corona constricted at the base. 



On the whole the vegetative structure of R. autoica is clearly 

 described in the original publication. When it states, however, 

 that the axis gives ofif branches on one side and stolons on the 

 other, a somewhat inconstant feature is emphasized as a specific 

 character. When the plants are scattered and the axes are attached 

 to the substratum by the ventral face, the branches on each side tend 

 to be photosynthetic in character, and few or no stolons are pro- 

 duced. It is only when the plants become more crowded, so that 

 the axes are attached by one edge, that the formation of stolons 

 on one side and of photosynthetic branches on the other becomes 

 a more usual phenomenon. 



