C. D. Walcott — Brachiopod Fauna of Rkode Island. 327 



Abt. XXXIII. — Note on the Brachiopod Fauna of the 

 Quartzitic Pebbles of the Carboniferous Conglomerates of 

 the Narragansett Basin, Rhode island ; by Chakles D. 

 Walcott. 



The first notice we have of the fossiliferous pebbles of the 

 Carboniferous conglomerates of the Narragansett Basin is by 

 Professor Wm. B. Kogers, who in 1861 announced the discovery 

 by Mr. Norman Easton of pebbles carrying fossils of the Pots- 

 dam fauna in the Carboniferous conglomerate north of Fall 

 River, Mass. Professor Rogers thought the forms distinctly 

 recognizable to be Lingula of two species, L. prima and Ju. 

 antiqua Emmons.* 



In 1875 Professor Rogers announced the discovery of 

 impressions suggestive of the foseil Lingular mentioned by 

 him from Fall River in the pebbles in the conglomerate at 

 Newport, Rhode Island.f He thought that the pebbles were 

 derived from rocks probably closely connected in time with 

 the Braintree Paradoxides beds. 



During the past two or three years Professor N. S. Shaler 

 and Mr. J. B. Wood worth have been sending me fossiliferous 

 pebbles picked up on the beach on the northern shore of 

 Martha's Vineyard, and at several points along the shore of 

 Narragansett Bay. Among these I find remains of two 

 large Linguloid brachiopods which appear to be identical with 

 Obolus (Lingidobolus) affinis Billings and 0. (X.) spissus 

 Billings, from the Lower Ordovician rocks of Great Belle 

 Island of Newfoundland. The material is somewhat imper- 

 fect, but in comparing it with the series of specimens from 

 the typical locality in Newfoundland, the two species appear 

 to be present. There is also a new species, which I have 

 named Obolus {Lingulelld) rogersi, which occurs both in the 

 quartzitic pebbles in the Narragansett Basin, and with O. (Z.) 

 affinis and 0. (Z.) spissus in Newfoundland. 



The geologic horizon of the sandstones on Great Belle 

 Island which carry the brachiopods is not far above the shales 

 carrying an Upper Cambrian fauna. It is quite probable that 

 the horizon represents the passage beds between the Cambrian 

 and Lower Ordovician. 



The exact locality from which the quartzitic pebbles of the 



* The Fossiliferous Pebbles of the Potsdam and Carboniferous Conglomerate 

 North of Fall River, Mass. ; Boston Soc. Nat. Hist. Proc, vol. vii, 1861, pp. 

 389-391. 



fOn the Newport Conglomerate; Boston Soc. Nat. Hist. Proe., vol. xviii, 

 1875, p. 100. 



