THE THALLOSE HEPATICAE OI' THE JUAN lEKNANDEZ ISLANDS 56 I 



The description just given is drawn from robust material, which naturally 

 brings out the distinctive features of the species most clearly. Some of the 

 specimens from Cumberland Hay, however, esi^ecially those collected on the 

 wettest parts of the back wall, arc greatly etiolated, the main axes are often 

 only 0.4 — 0.6 nnn. wide, the narrow primary branches are sometimes more than 

 I mm. apart, and secondary branches are relatively infrecjuent. These specimens, 

 however, show crenulatc wings of the characteristic type, and the few sexual 

 branches present are essentially like those on the more vigorous plants. 



There are two species of the Chilean mainland to which /v. bveviramosa 

 is obviously related. One of these is A', autoica (Steph.) Evans, which is usu- 

 ally dioicous in spite of its name, and the other is R. tencrriuia (Steph.) Evans, 

 which is normally autoicous. Both of these species have recently been described 

 and figured by the writer.^ In R. autoica the prostrate axis is adherent to the 

 substratum by means of rhizoids; the differentiation into various types of branches 

 is usually far more evident than in R. hrevirainosa\ the cells are distinctly 

 smaller, both the surface cells and those of the interior averaging only 30 {x in 

 width; the male inflorescence is more complex, the openings into the antheridial 

 chambers being separated by three or four rows of cells; and the involucre of 

 the female inflorescence, which is directed forward rather than upward, is ciliate 

 but no lobate. In R. tencrriuia the whole thallus is adherent to the substratum 

 and is thinner and much more delicate than that of R. breviramosa, although 

 the interior cells a\erage only 50 ij, in width. The female inflorescence, more- 

 over, is shorter, the archegonia are fewer, and the wings are narrower and 

 subentire. 



The crenulate wings of R. breinramosa will at once recall the very similar 

 structures found in R. viultifida (L.) S. F. Gray, a common and widely distrib- 

 uted species of Europe, Asia and North America. It is not surprising, there- 

 fore, that Mitten referred the scanty and sterile Masatierra material at his 

 disposal to this northern plant. He stated, however, that his determination 

 was merely provisional. On the whole R. niultifida is narrower and thinner, 

 the axis being only 0.5 — i mm. wide and four to seven cells thick; and the 

 branching tends to be more definitely bipinnate, the secondary branches being 

 longer. The inflorescence, moreover, is autoicous, and the involucre of the 

 female inflorescence is ciliate rather than lobate. 



Area of distribution. Falkland Islands; Juan Fernandez. 



•••9. R. adglutinata nov. spec. — Fig. 2, A— C. 



Growing in depressed mats, dull green, often becoming tinged with yellowish 

 or reddish brown in the older parts, usually opaque: thallus postrate throughout 

 and more or less closely adherent to the substratum; axis flattened, sometimes 

 wingless but often bordered by a wing one or two cells wide; branches close 

 together or somewhat distant, sometimes equalling the axis in width but shorter 

 and often narrower, irregularly once or twice pinnate, the ultimate branches often 

 persisting as rudiments, marginal wing if present often two or three cells wide and 

 sometimes crenulate: inflorescence autoicous: ^ inflorescences borne singly or 



Trans. Connecticut Acad. 25 159. 164 f. 7 and 8, A, B (1921). 



