- 
218 T. S. Hunt on Ophiolites. 
n 
represented by silica 
ate 0: 
cose serpentine. In addition to these, the'same author describes 
. 
an 
tes from 
brecetas, 
erate, or breeciated in their structure. I have been om vv 
ticular in distinguishing these different varieties, because mt 
“have doubtless a common origin, and because their study 
