

walcott.] EASTERN MASSACHUSETTS. 75 



In arranging the collections of the State cabinet of Massachusetts, 

 Dr. Edward Hitchcock placed the rock near Boston which carries the 

 trilobites in the Silurian and Cambrian. 1 



Prof. W. B. Rogers sent to Mons. J. Barrande 2 a photograph of the 

 Paradoxides found at Braintree. Barrande compared it with Paradox- 

 ides spinosus and concluded that Paradoxides harlani was a synonym of 

 Paradoxides spinosus. 



In 18G1 Prof. Rogers 3 announced the discovery by Mr. Norman Eas- 

 ton of pebbles carrying fossils of the Potsdam fauna in Carboniferous 

 conglomerate north of Fall River, Massachusetts. He thought the forms 

 distinctly recognized in the pebbles were Lingula of two species, resem- 

 bling Lwgula prima and L.antiqua of Emmons, from the Potsdam sand- 

 stone of New York, and that the rocks from which the pebbles were 

 derived were probably closely connected in time with the period of the 

 Braintree Paradoxides beds. The conglomerate in which the pebbles 

 occur is considered to be of Carboniferous age. 



Various communications were made to the Boston Society of Natural 

 History respecting the Paradoxides fauna at Braintree, by Messrs. 

 Jules Marcou and C. T. Jackson in 18G1 and 18G2. From that time 

 until 1869 little attention appears to have been given to the Braintree 

 rocks. In the latter year Prof. N. S. Shaler 4 described the rocks in the 

 viciuity of Boston, and referred to the argillites of Braintree, stating 

 that they were deposited in deep water. In 1870 Dr. T. S. Hunt ex- 

 amined the rocks near Braintree, and stated that the unaltered argil- 

 lites of Braintree, holding the Primordial fauna, were observed by Prof. 

 Shaler and himself to rest directly upon a hard porphyrite felsite of 

 the ancient series. He says: 5 



The fact that the Primordial strata of Braintree have suffered no metamorphism is 

 the more signiGcant, since the beds of similar age in New Brunswick and Newfound- 

 laud rest unconforinably on crystalline strata supposed to belong to the same ancient 

 series that underlies the Braintree beds, and are, like these, unaltered sand and mud 

 rocks. 



In 1875 Mr. W. W. Dodge 6 described the rocks at and about Brain- 

 tree in the Boston Basin with great detail, and accompanied this with 

 a discussion of the correlation of the Paradoxides beds with the various 

 lower Paleozoic rocks of Europe. 



In the same year, in some remarks on Massachusetts geology, Dr. T. 

 S. Hunt 7 reaffirms his observation on the relations of the fossiliferous 



'[Catalogue of State cabinet and notes on mctaraorphic rocksl 6th annual report of the Secretary 

 of Massachusetts Board of Agriculture, etc., by Charles L. Flint, Boston, 1859, p. iv. 



2 Trilobiten der Primordial-fauna in Massachusetts. Neues Jahrb. fur Mineral., I860., pp. 429-431. 



3 Ou fossiliferous pebbles of Potsdam rocks in Carboniferous ( nglunerate north of Fall Kiver, 

 Massachusetts. Boston Soc. Nat. Hist., Proc, vol. 7, 1861, pp. 3S9-o ( Jl. 



4 Ou tbe relations of the rocks in the vicinity of Boston. Boston Soc. Nat. Hist., Proc, vol 13, 1869, 

 pp. 172-178. 



6 On the geology of the vicinity of Boston. Boston Soc. Nat. Hist., Proc, vol. 14, 1871, p. 48. 



6 Notes on the geology of eastern Massachusetts. Boston Soc. Nat. Hist., Proc, vol. 17, 1875, pp. 

 388-419. 



7 [Remarks on Massachusetts geology.] Boston Soc. Nat. Hist., Proc, vol. 17, 1875, pp. 508-510. 



