PLATE 1. 
PLATE 2. 
PLATE 3. 
PLATE 4. 
PLATE 5. 
PLATE 6. 
PLATE 7. 
EXPLANATION OF PLATES. 
Shapes of pebbles in the conglomerate: A, angular; B, subangular; 
C, rounded; D, rounded, with some well rounded. 
Conglomerate ledge, North Beacon St., Brighton, showing lenticu- 
lar (A) and rounded (B) types of the so-called slate pebbles. 
A. Conglomerate at Squantum showing a large granitic boulder 
embedded among smaller pebbles. B. Deformed pebbles in 
the conglomerate at Purgatory near Newport, R. I. The ham- 
mer handle is 18 inches long. 
East (A) and south (B) sides of a ledge a few hundred yards north- 
east of the sharp bend in Commonwealth Ave., Brighton, showing 
(A) melaphyr cutting across the bedding of sandstone in irregular 
vertical contact and (B) an irregular strip of sandstone included 
in the melaphyr. 
Deformed conglomerate at Fogland Point, R. I., showing (A) the 
bedding of the rock and the stretching of the pebbles; (B) 
flattened, sliced, indented and striated pebbles. The hammer 
handle is 18 inches long. 
Geological section southeastward from the asylum grounds at Bel- 
mont 
Topographical and geological map. 
