Bulletin of the Museum of Comparative Zoölogy 
Ail HARVARD COLLEGE. 
Vol XLIX. 
GEOLOGICAL SERIES, Vol. VIII, No. 4. 
THE ORIGIN AND STRUCTURE OF THE ROXBURY 
CONGLOMERATE. 
By GEORGE Rogers MANSFIELD, 
— 
WITH Seven PLATES. 
CAMBRIDGE, MASS., U. S. A.: 
PRINTED FOR THE MUSEUM. 
NovemBrr, 1906. 
