THE TIIALLOSK HKPATICAE OF THE JUAN FERNANDEZ ISLANDS 585 



tlie ridges are subject to a good deal of variation. Those of the outer series, 

 for example, ma\' be irregular in arrangement, some being nearer the periphery 

 than others; they may vary in the degree of their curvature, some being slightly 

 curved or almost straight; and their convexities may be turned in various di- 

 rections, instead of being all directed inwards. In the inner scries the ridges, 

 instead of forming a circle, may have wavy outlines or turn their convexities 

 inward. In some cases the ridges are fewer, and this reduction in number 

 may be associated with further irregularities. 



The ridges on the spores of A. Skottsbcrgii represent an unusual feature. 

 Stepii.\M, in this writings, makes no mention of s[)ore-markings of this type 

 in Anthoccros, and apparently the only species with which such markings have 

 been associated is A. Peursoni M. A. Howe of western North America.' In 

 the northern species, however, the spores are only 36 |j. in diameter, and the 

 ridges are fewer, shorter, and grouped together in the central portion of the 

 spherical face, leaving a broad peripheral zone free from ridges. In their 

 arrangement, moreover, the ridges show marked irregularity. 



The pale brownish pseudo-elaters of A. Skottsbergii are mostly 5c — 250 {j, 

 in length and 6— 12 '^j, in diameter. They are often variously bent or contorted 

 and are sometimes branched, their cells vary in number from one to four, and 

 their slightly thickened outer walls are often wavy. 



Area of distribution: Endemic. 



Megaceros Campbell. 



^ly. Megaceros fuegiensis Steph. Kungl. Svenska Vet.-Akad, Handl. 

 46^91 (1911). 



On moist rocks and soil. 



Masatierra: O. Damajuana, waterfall in forest, 248 m. (no. 113). 



Masafiiera: Q. de las Casas, among stones, innermost accessible part, 

 248 m. (no. 114). 



The determination of these Juan Fernandez specimens as M. fnegioisis 

 must be regarded as provisional. The genus Megaceros is in need of careful 

 revision. Except in the case of a few Indo-Malayan representatives, which have 

 been thoroughly described by SCHIFFNER, Campbell, and GOEBEL, our knowl- 

 edge of the species is exceedingly incomplete, and it is rarely possible to 

 determine a specimen by means of the published descriptions alone. In the 

 present case two courses were open: first, to make the specimens the type of 

 a new species; or, second, to refer them to a published species, even if they 

 did not agree with the descriptions in every detail. Since the specimens, although 

 fertile, are not abundant, the second course seemed preferable. It should perhaps 

 be noted that Stephani did not include J/, fuegiensis in his Species Hepat- 

 icarum, published in 1916. The only species that he lists from southern South 

 America is M. endiviaefolius (Mont.) Steph., reported simply from »Fretum 

 magellanicum.s This species is more robust than the specimens listed above 

 and is characterized by the lacerate and crispate margins of the thkllus. 



^ Bull. Torrey Club 25: 8 pi. 522, 323 (1! 



