2(54 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
LITERATURE. 
Benton, E. R. 
’78. The Richmond boulder trains. Bull. Mus. comp, zooh, vol. 5, p. 17- 
43, 2 maps. 
Chamberlain, T. C. 
’88. The rock-scorings of the great ice invasions. Seventh Ann. rept. U. S. 
geol. surv., 1885-8(1, p. 156-248, pi. 8. 
Crosby, W. O. 
’91. Composition of the till or boulder clay. Proc. Bost. soc. mat. hist., vol. 
25, p. 115-140. 
Crosby, W. 0. 
’94. Geology of the Boston Basin. Part 2, Hingham. Occasional papers, 
Boston soc. nat. hist, IY, vol. 1. 
Crosby, W. O. 
’96. Englacial drift. Technology quart., vol. 9, p. 116-144. 
Crosby, W. O., and Grabau, A. W. 
’96. Glacial lakes of the Boston Basin. Amer. geol., vol. 17, p. 128-130. 
Lyell, Charles. 
'55. On certain trains of erratic blocks on the western borders of Massa¬ 
chusetts, United States. Proc. Royal inst. Gt. Britain, vol. 2, p. 86-97. 
See also, Antiquity of man. N. Y., 1871, p. 355. 
Shaler, N. S. 
’93. The conditions of erosion beneath deep glaciers, based upon a study of 
the boulder train from Iron Ilill, Cumberland, R. I. Bull. Mus. comp, 
zool., vol. 16, p. 185-225, 4 pis., map. 
Printed , June , 180S. 
