1871.] 199 [Perry. 



Professor J. B. Perry said : — 



It is perhaps fitting for me to offer a few remarks on the "Eozoon" 

 limestone of eastern Massachusetts, since I have been long engaged 

 in the study of the foliated (or Laurentian) series of rocks, in which 

 it occurs; insomuch, also, as I discovered many years ago what 

 seemed to me indubitable evidence that portions of this limestone 

 are of vein-like origin ; and because I was the first to suggest, and 

 really to make out, that some of the limestones of eastern Massachu- 

 setts have a similar vein-structure. It likewise properly devolves 

 upon me to say something at this time, as, after visiting Chelms- 

 ford, and satisfying myself in regard to the actual character of the 

 calcareous masses containing the supposed organic remains, I agreed 

 to present some of the more important points bearing on the strati- 

 graphy of the rocks, whenever my friend, Mr. Burbank, of Lowell, 

 should be ready to discuss the existing evidence, and especially that 

 furnished by the microscope, as to the organic or inorganic character 

 of the enclosed " Eozoon." 



As geologists have generally supposed that all limestones are strat- 

 ified rocks, a few words may be requisite on this point. They are 

 more especially needful at the present time, and in connection with 

 the subject under consideration, as they may serve to meet an objec- 

 tion which is likely to occur to many minds, — particularly such as 

 hold to the organic, or " sedimentary " derivation of all limestones. 

 It is true that Dr. Emmons, as is well known, endeavored to show 

 that limestones occur, not only as stratified beds, but also as intrusive 

 masses; but this doctrine was never widely received, however much 

 truth may have lain concealed at its foundation. Beginning my study 

 of the limestones connected with the foliated series of rocks, in the 

 light of this view, I finally became convinced in 1861, and set forth 

 in a course of lectures delivered during the same year, that some of 

 these limestones in Vermont and New York have a vein-like struc- 

 ture, and should be regarded as true vein-stones. Having entered 

 anew, some four or five years ago, upon the study of the rocks of 

 eastern Massachusetts, I at once became convinced that limestones 

 in Stoneham, Newbury, and some other townships in this portion of 

 the State, are also vein-rocks. 



Such limestones are to be met with, as has been in part already 

 implied, in association with the foliated series of rocks, both in east- 

 ern and western Vermont, and in various parts of Massachusetts. 



