390 



On the river bank, and elsewhere in this vicinity, are many 

 loose boulders, some of them of large dimensions, composed of 

 a very coarse conglomerate similar in aspect to the solid ledges 

 which have their outcrop in Somerset, Dighton, and other tracts 

 toward the North. Sagaciously pursuing the inquiry, Mr. Easton 

 recognized the identity in lithological characters of the fossilifer- 

 ous fragments with many of the pebbles included in these con- 

 glomerate boulders, and at length succeeded in detecting the 

 fossils themselves in some of these imbedded pebbles. 



In a visit to the neighborhood early in the summer. Prof. 

 Rogers, in company with Mr. Easton and Mr. Shove, collected 

 specimens from the loose stone heaps and boulders at Fall River, 

 and, on a brief examination of the ledges of conglomerate in 

 Dighton, found similar fossiliferous pebbles in the massive rock 

 in place at that locality. 



The fossil forms distinctly recognized in these specimens are 

 Lingulce of probably two species, resembling L. prima and L. 

 antiqua of the Potsdam (Primal white) sandstone more nearly 

 than any others with which they have thus far been compared. 

 More perfect specimens and a wider comparison may, however, 

 be necessary to give entire certainty to their determination. 



This discovery is obviously but a first, though a most encourag- 

 ing, step in our inquiries. The question is at once suggested, 

 Where are we to look for the parent rock from which these peb- 

 bles were derived? And to answer this it will be necessary 

 to make a thorough examination of the sedimentary masses of 

 adjacent and perhaps somewhat remote regions, of which un- 

 fortunately so large a part is concealed by the covering of 

 drift. 



The coal measures of Rhode Island and the contiguous parts 

 of Massachusetts have afforded a sufficient number of well- 

 determined fossils to leave no doubt in the minds of geologists 

 as to their general correspondence in period with the great Car- 

 boniferous system of this and other countries. But in regard to 

 the age of most of the other rocky masses of Rhode Island and 

 eastern Massachusetts we are yet without the means of forming 

 any definite conclusion. The locality in Braintree in the latter 

 region, signalized by the occurrence of that superb fossil Para- 

 doxides spinosus {Harlani)^ presents us with a specimen of one 



