262 Proceedings of the Uoycd Fhysical Society. 



angles to the coast-line. Between it and the peperino there 

 was a small knob of rock, seemingly also intrusive, which 

 contained many large augite crystals ; in fact, these formed 

 by far the larger part of the rock mass. 



Besides these rocks found in situ, some specimens were 

 taken from boulders in the stream as giving some indication 

 of the rocks occurring farther inland. The samples were 

 picked from rocks evidently different from those seen in situ. 

 A grey, almost homogeneous rock (No. 14) was particularly 

 common. Others were red and brown trachyte-like rocks, 

 and a sample of grey compact tuff was also obtained. All 

 were volcanic with the exception of one small piece of lime- 

 stone, picked up at the mouth of the stream. Had this been 

 found in situ, its occurrence would be a very strong argument 

 in favour of the former existence of a great land area between 

 South Africa and South America. But as there is the double 

 possibility of its having been carried there by an iceberg or 

 by some of the sealers who have visited the island, no positive 

 conclusions can be drawn from it. Mr Schwarz has already 

 stated 1 pretty strongly, on the evidence of a piece of gneiss 

 picked up on Tristan da Cunha, the petrographical evidence 

 in favour of a " Flabellites Land," occupying the greater part 

 of what is now the basin of the South Atlantic. 



1 Schwarz, "Rocks of Tristan d'Acunlia," Trans. South African Phil. Soc, 

 1905, vol. xvi. part i. See also Riulniose- Brown, " Diego Alvarez or Gough 

 Island," Scot. Geog. Mag., 1905, p. 430. L. V. Pirsson, "Notes on some 

 Volcanic Rocks from Gougli's Island," Am. Jour, of Science, 1893, p. 380. 



