4 i 4 SCIENCE PROGRESS. 



(7) MURCHISON and Geikie. Quart. Jour. Geo/. Soc, p. 232 ct 



seq., 1 86 1. 



(8) KoHLER, G. Jahrschrift fur Bergwesen, s. 195, Berlin, 



1880. 



(9) Geikie, Peach and Horne. Nature, pp. 29-35, 1884-85. 



W. F. Hume. 

 (To be continued.) 



