486 Crosby and Ballard — Distribution and Age of 



Art. LXY. — Distribution and Probable Age of the Fossil 

 Shells in the Drumlins of the Boston Basin ; by W. O. 

 Crosby and Hetty O. Ballard. 



So long ago as during the Revolutionary war, Gen. Benjamin 

 Lincoln noted that in digging a well 90 feet deep in the fort 

 on Telegraph Hill, in Hull, many shells were found, the shells 

 extending from near the top of the ground to the bottom of 

 the well." Seventy-five years ago it was recorded that frag- 

 ments of clam shells had been found 40 feet below the surface 

 at Jamaica Plain, and at the depth of 107 feet in digging the 

 well at Fort Strong, which was built in 1814 on Noddle's 

 Island, now East Boston. f 



But the first observer to note the occurrence of shells in the 

 natural sections of the drift hills in the vicinity of Boston was 

 Dr. William Stimpson, who published in 1851 a list of the 

 fourteen species named below, which he found in the sea-cliff 

 at "Winthrop Great Head, then a part of Chelsea \% Balanus 

 crenatus, Chrysodomus decemcostatus, Tritia triviiatta, Uro- 

 salpinx cinerea, My a arenaria, Ensatella americana, Mactra 

 solidissima, Yenus mercenaria* Cyclocardia borealis, Astarte 

 undata, Astarte castanea, Mytilus cdidis, Modiola modiolus* 

 Ostrea virginiana. About twenty-five years ago, in digging 

 a well in Fort Warren on George's Island, shells were found 

 100 feet below the surface and about 40 feet below the sea 

 level.§ In 1888 Mr. W. W. Dodge added, doubtfully, three 

 species — Lacuna neritoidea, Tapes fuctuosa, and Cardium 

 islandicum — to Stimpson's list from the Great Head section ;|| 

 and noted the occurrence of shells in Grover's Cliff on the 

 northeast shore of Winthrop, nearly one and a half miles north 

 of Great Head.*j~ 



Stimpson believed that the shells were contemporaneous 

 with the enclosing drift, and regarded them as evidence of a 

 marine submergence within the Pleistocene or Quaternary 

 period. This view appears to have been generally accepted, 

 or at least not to have been questioned, until 1886, when Lewis 



* Geographical Gazetteer of the Towns in the Commonwealth of Massachusetts, 

 1785, p. 56. (Only a small part of this work was published.) 



f Outlines of the Mineralogy and Geology of Boston and its vicinity, with a 

 geological map. By J. Freeman Dana, M.D., and Samuel L.Dana, M.D., 1818, p. 96. 



X Proc. Boston Soc. Nat. Hist., vol. iv, p. 9. 



§ Reported by Prof. W. H. Niles in the Proc. Boston Soc. Nat. Hist., vol. xii, 

 1869, pp. 244 and 364. In commenting on this discovery Mr. T. T. Bouve read a 

 letter from a gentleman in Hull noting similar facts known to him in his own 

 vicinity (p. 364). 



|| This Journal, III, vol. sxxvi, p. 56. 



*[[ Proc. Boston Soc. Nat. Hist., vol. xxiv, p. 129. 



