446 SHIMER. 



Feet 



1. Fill, blotting out the Back Bay 19 



2. Dark grey loamy silt, prominently stratified .... 12 



a. Upper 8 feet contained 



Mya arenaria c. Large. 



Ensis directus C. 



Mulinia lateralis 



Gemma gemma 



Modiolus demissus, var. plicatulus r. 



Ostrea virginica c, but comparatively small, including 

 both current and quiet water forms. These were noted 

 directly beneath the fill. On account of the absence 

 of oysters between this and the stratum of large current 

 oysters below, it is believed that these smaller oysters did 

 not grow here but are due to man's agency. 



Mytilis edulis r 



Ilyanassa obsoleta r 



Balanus cf . balanoides r 



b. Lower 4 feet contained 



Ostrea virginica C; similar to the very large current forms 



so common at the Charles River locality. 

 Venus mercenaria c 

 Mulinia lateralis C 

 Gemma gemma C 

 Littorina palliata c 

 Ilyanassa obsoleta C 

 Nassa trivittata r 

 Polinices heros r 

 Crepidula plana r 

 C. fornicata r 



Cliona sulphurea r. Noted on oyster shells. 

 Crab claws r 

 Fish vertebra R 

 Besides these, Macoma balthica was abundant, but its exact 

 position in 2 was not noted. 



3. Blue glacial clay, at a depth of 31 feet. No unconformity was 



observed in the ten foot wide section studied. 



To the west of Berkeley Street, nearly in front of the Rogers Building 

 (M. I. T.) occurred sticks in both vertical and horizontal positions, 

 apparently a portion of an old fish-weir. The length of the vertical 

 ones varied according to different observers from four to seven feet. 

 They usually penetrated the blue clay, one to a depth of eighteen 



