488 Crosby and Ballard — Distribution and Age of 



In connection with a systematic study of the geology of the 

 Boston Basin, we have made a careful search for fossils in all 

 the deep drift sections now accessible, more than doubling the 

 number of localities and extending the list of species from 

 twenty-six to forty-seven. Following is a list of the twenty- 

 one new species which we have added to the drift fauna. 

 Cancer irroratus, Balanus balanoides, Fusus tomatus, Nep- 

 tunea pygmcea, iSipho spitzbergensis, Buccinicm cyaneum. 

 Purpura lapilhis, Anachis avara, Lunatia triseriata, Crepi- 

 dula convexa, Crepidula plana, Crepidida fornicata, Zirfcea 



hunt. 



Map of Boston Harbor, showing the distribution of the fossiliferous drift sections. 

 Scale, 1 inch=4 miles. 



I, Grover's Cliff ; II, Winthrop Great Head; III, Deer Island; IV, Moon 

 Island; V, West End of Long Island; VI, Long Island Head; VII, Lovell's 

 Island; VIII, George's Island; IX, Great Brewster Island; X, Quincy Great 

 Hill; XI, Nut Island; XII. Princess Head; XIII, XIV, XV, XVI, Peddock's 

 Island; XVII, Telegraph Hill, Hull; XVIII, Point Allerton, Hull; XIX, Straw- 

 berry Hill, Hull; XX, Sagamore Head, Hull; XXI, well on James' Hill, Cohasset; 

 XXII, well in Braintree; XXIII, well in Jamaica Plain; XXIV, well in East 

 Boston. 



