Puate IV.-

A. Microphotograph of polished ore from Rocher
De Boule mine, magnified 250 diameters. Chaleopy-
rite veining hornblende (first mineralization). 1,
hornblende; 2, chalcopyrite; 3, quartz. (Page 12.)

B. Microphotograph of polished ore from Rocher
De Boule mine, magnified 200 diameters. Hornblende
(actinolite) replacing chalcopyrite of the first mineral-
ization. 1, magnetite; 2, pyrrhotite; 3, chalcopyrite;
4, actinolite; 5, pyrite. Paragenesis—l, Ona 3, 4.
(Page 12.)