Ki. 



KXPLANATION OF PLATE. 



Pioii (ieoioi;. i>l tlic Boston Basin " liy W. i^. Crosliv , in Bus. s<)<;. Sat. Hist., 

 Opf,■^>i<lna^P«]^^?r^i. vol. 4, pan 1. 



Naiural .-iection of 'the Inclined cfoiitile dike (ii+iiii the western 

 eud .if Rocky Neck'.   '•','■•■■. ■.vhkm :■ , . 



Ku;. 'J. T>ike 157 cnttinsr a ledge of granite^'' fv^'^Wltite Head, on 

 Hominy point. Cohasset. ivi wi Ariaiitif .-ui.i < 



Vu;. 3. A highly brecciate<l portion of ; the thin bed of indurated tuff 

 on Long Beach rocli. 



