THE BOTANY OF THE SOUTH ORKNEYS. 25 



With regard to the Antarctic lichens, on the other hand, we have three difficulties 

 to contend with. The limits of the Antarctic regions do not admit of easy definition. 

 We have, secondly, no very extensive and exhaustive collections from certain limited 

 areas, but rather a sample taken here and a sample taken there, in localities to which 

 often flying visits ouly have been paid by expeditions. This becomes the case more and 

 more the farther south we go. Of course the scattered nature of the land, which may be 

 included in the term Antarctic, is largely responsible for this being the case. Lastly, we 

 are still in want of a critical examination of all the herbarium material that has so far 

 been collected, and all that there is to be found in the literature. There must be a 

 sufficiently great quantity of material in European an'd American herbaria, and in the 

 literature of the subject, to make such a critical examination a fairly hopeful under- 

 taking. But a compilation of the printed records must be accompanied by a critical 

 examination of the corresponding herbarium specimens. 



Till this herculean task has been successfully accomplished we must confine our 

 energies to getting hold of every possible morsel of lichen material from the Antarctic 

 regions and carefully recording name and locality. From this point of view the lichens 

 brought back by the Scottish National Antarctic Expedition, and collected by Mr R. N. 

 Rudmose Brown, are very interesting and valuable. Eleven species were collected at 

 the South Orkneys. 



I will now enumerate the species, adding any observations that may appear 

 necessary, and then make some more general remarks on the distribution of Antarctic 

 lichens. 



LECIDEA FUSCO-ATRA (L.), Tli. Fr. Occurs in the Arctic regions. South Orkneys. 



RHIZOCARPON GEOGRAPHICUM (L.), D.C. Found on rocks in Scotia Bay, South 

 Orkneys. It is a cosmopolitan species, being frequently met with in the Arctic regions, 

 and it may also be described as being a typical Alpine plant. 



GYROPHORA VELLEA (L.], Ach. (or VELLEREA (L.), Ach,, according to Arnold) was 

 collected on rocks on the south-west shore of Scotia Bay rising to a height of 1000 

 feet. It was also collected on Saddle Island at a height of 300 feet. The specimens 

 were all well developed, one measuring as much as 11 by 20 cm. The latter was found 

 growing in close association with Usnea melaxantha, Ach., some plants of which were 

 actually firmly attached to the surface of the Gyrophora plant. Gyrophora vellea is 

 recorded from America and Europe, being an Arctic and Alpine plant. 



CLADONIA FIMBRIATA (L.), Fr. This species, though otherwise cosmopolitan in 

 distribution, does not occur in the extreme Arctic regions, and its discovery in the 

 South Orkneys, where it was found between moss in Scotia Bay, is of great interest. 



CLADONIA DEFORMIS (Ach.), Hffni. A few specimens of a Cladonia brought from 

 Scotia Bay, South Orkneys, seem to belong to this species. It is again cosmopolitan, 



being also a typical Arctic and Alpine plant. 

 VOL. III. 



