GEOLOGICAL AND MINERALOGICAL NOTES. 157 



of plainly stratified sediments of calcite, quartz grains, 

 epidote, chlorite, some magnetite and limonite and to be 

 of the same character as that at Mill cove, North Wey- 

 mouth. The fossils found at this outcrop which can be 

 identified are all in the cherty limestone. They comprise 

 numerous fragments of species of Hyolithes and several 

 sections of a rare ( ?) Archaeocyathus of the lower Cam- 

 brian. These fossils were identified by Mr. Chas. D. 

 Walcott of the U. S. Geological Surve}% Washington. 

 The strike of this deposit is 20 north of east to southwest, 

 dip 40 west, which is nearly parallel to the strike of the 

 Olenellus Cambrian deposit at Nahant head. Another 

 outcrop of these Cambrian rocks is in Topsfield, in the 

 southwest part of the town near the Ipswich river. It is 

 composed of the same succession of schistose argil lite 

 shales, ferruginous sandstone, and a cherty limestone that 

 is near lydite. Although fossils have not as yet been 

 found in this limestone, numerous fossil casts are seen in 

 the schistose argillite shales which were instantly recog- 

 nized as annelids by Mr. Walcott. Some of these casts 

 were from three to six inches long and one quarter of an 

 inch thick. Other outcrops have been found at Archelaus 

 hill in West Newbury at an elevation of nearly two hun- 

 dred feet, Ward's hill in Bradford, in the bed of the 

 Merrimac river in red argillite shales, and on the high 

 hills of Methuen at an elevation of one hundred feet. Fos- 

 sils which can be recognized as species have not been 

 detected in these last named outcrops, but enough have 

 been found to warrant the determination of these strati- 

 fied beds as parts of the crystalline Cambrian sediments. 

 The inference drawn in explanation of the presence of 

 these Cambrian deposits scattered over the county is, that 

 during the Cambrian period there was a vast sheet of these 

 sediments deposited over the entire region to the depth of 



ESSEX INST. BULLETIN, VOL. XXIII 10* 



