28 DISCOVERY REPORTS 



penguin rookeries. Mastodia avoids such extremely nitrogenous positions. In rock gutters, where a 

 trickle of strongly ammoniacal drainage seeps over periodically from a source higher up, its passage is 

 often intercepted first by a mat of the Prasiola, which apparently filters out the most highly concen- 

 trated constituents, solid matter, feathers, etc. ; the Mastodia, often grading into the Prasiola, occurs 

 on the side away from the source, thus encountering clearer and presumably less nitrogenous drainage 

 water. 



Associated species are Caloplaca elegans, Xanthoria lychnea (often epiphytic on the Mastodia), 

 Biiellia spp., Lecania (Thamnolecania) Brialmontii and Verrucaria elaeoplaca. The latter species is more 

 hydrophilous, replacing Mastodia in the central portions of seepage channels (PI. Ill, fig. i). 



M. tesselata has a preference for the harder types of rock (granodiorite, andesite, etc.). On Goudier 

 Islet I noticed that it avoided certain fine-grained patches, of acid composition, in the granodiorite. 

 An abnormal habitat was the weathered wooden deck of an old whaling scow which had lain on the 

 beach for many years. 



Geographical Distribution. Bipolar. In the northern hemisphere it occurs in eastern arctic 

 Siberia (Pitlekai, Behring Straits), and is apparently altogether absent from the western Arctic; in the 

 southern hemisphere, Kerguelen, South Georgia, Graham Land and adjacent islands, and Fuegia. 

 The following is a list of the antarctic localities from which it has previously been recorded : 



South Shetlands. Nelson Island {T)2t.rh\s\{\re, 1912). 



West Graham Land. Trinity Peninsida, north coast: Astrolabe Island and small islet off the coast 

 (Darbishire, 191 2). Palmer Archipelago: Port Lockroy, Goudier Islet (Hue, 191 5); Bob Islet off 

 Wiencke Island (Vainio, 1903). Mainland coast betzveen Cape Charles and Cape Renard: Cape Van 

 Beneden (Vainio, 1903). Kaiser Wilhelm II Archipelago: Booth Island (Hue, 1909); Hovgaard Island 

 (Hue, 1915). 



East Graham Land. Erebus and Terror Gulf: Paulet Island (Darbishire, 1912). James Ross Island: 

 west side, about lat. 64° (Darbishire, 191 2). 



[South Georgia. Royal Bay (Reinsch, 1890); Maiviken (May Harbour) (Darbishire, 1912).] 



LIST OF LITERATURE 



ACHARIUS, E., 1798. Lichenographiae Suecicae Prodromus. Linkoping. 

 1803. Methodus qua omnes detectos Lichenes. Stockholm. 



1810. Lichenographia Universalis. Gottingen. 



Blackman, V. H., 1902. Lichenes. Report on the collections of natural history made in the Antarctic regions during the 



voyage of the 'Southern Cross', p. 320. 

 Branth, J. S. D. and Rostrup, E., 1869. Lichenes Daniae eller Danmarks Laver. Bot. Tidsskr., iii, p. 127. 

 Calman, W. T., 1937. James Eights, a pioneer antarctic naturalist. Proc. Linn. Soc. Lond., 149th session, p. 171. 

 Cengia Sambo, M., 1926. / licheni delta Terra del Fuoco. Contrib. Scient. Missioni Salesiane Ven. Don Bosco. 

 Crombie, J. M., 1876. Lichenes Terrae Kergueleni. J. Linn. Soc. Lond., Bot., xv, p. 180. 

 1876 a. On the lichens collected by Professor R. O. Cunningham in the Falkland Islands, Fuegia, Patagonia, and the island of 



Chiloe during the voyage of H. M.S. 'Nassau', 1867-9. J. Linn. Soc. Lend., Bot., xv, p. 222. 

 Dalla Torre, K. W. and Sarnthein, L., 1902. Die Flechten (Lichenes) von Tirol, Vorarlberg und Liechtenstein. Innsbruck. 

 Darbishire, O. V., 1905. The Lichens of the South Orkneys. Trans. Proc. Bot. Soc. Edinburgh, xxiii, p. 105. 



1910. Lichenes. [British] Nat. Antarct. Exped. 1901-4, Nat. Hist., v. 



1912. The lichens of the Swedish Antarctic Expedition. Wiss. Ergebn. Schwed. Sudpolar-Exped. 1901-3, IV, Lief. 11. 



1912a. The lichens of the South Orkneys. Rep. Sci. Res. Voy. S.Y. 'Scotia', 1902-4, iii, p. 24. 



1923. Cryptograms from the Antarctic. J. Bot., lxi, p. 105. 



1923a. Lichens. Brit. Antarct. ('Terra Nova') Exped., 19 10, Nat. Hist. Rep., Bot., Part in, p. 29. 



Degelius, G., 1940. Contributions to the lichen flora of North America. L Ark. Bot., xxx a, no. i. 



