286 INDEX. 



Slate, Primordial, orthoelase crystals in, 263. 



pinite in, 263. 



pyrite in, 192, 255. 



quartz veins'in, 248. 



relations to amygdaloid, 238, 241, 247, 248. 



relations to conglomerate, 185-191, 207, 218, 222, 226, 227, 239. 241 

 244, 246, 249-250. 



relations to granite, 193, 194, 206-207, 208. 



relations to Naugus Head series, 195, 262-263. 



ripple-marked, 218, 238, 240-241, 247. 



thickness of, 203, 218, 226, 236-237, 258, 265-266. 



uniformity of, 191, 194, 195. 



See Primordial series, Conglomerate, and Shawmut group. 

 Slate Island, 209. 



Somerville, cause of south-east strike in, 261. 

 South Boston, rocks of, 235-237. 

 South-eastern Mass., thickness of drift in, 6. 

 Spectacle Island, rocks of, 226. 

 Squantum, rocks of, 222-223. 

 Stoneham, dolomite in, 115-116. 

 Swallow, Miss B. H., analysis of siderite, 115. 



Taconian series, relations to Montalban system, 179. 

 Thompson's Island, 226. 

 Toadstone in Newbury, 57-60. 



Wadsworth, M. B., exotic diabase, 22, 255, 256. 



micaceous granite of Cape Ann, ^8 



Wollastonite in Newbury, 113. 

 Western Mass., geology of, 126-127. 



