ERRATA. 



The last line on page 13 should be transferred to be the sixth line on page 14. 



On page 19, line 23, for twn-discovery read discovery. 



On page 119, 7th line fi'om the bottom, for neared read nearer. 



On page 24, last line, insert they. 



At variouus places in the catalogue of specimens for Linomite read Limonite. 



