SAYLES: THE SQUANTUM TILLITE. 161 
This will explain why some of the descriptions give so few glacial 
characters, and does not mean that such an outcrop would not reveal 
many more glacial characters if opportunity were granted to hammer 
and blast. 
In spite of the small outcrops and those which I have not been able 
to investigate properly, the average percentage of criteria for all 
localities so far as the present investigation has gone, is slightly over 
61%. Taking the first five of the localities given in the list, and the 
percentage of criteria is 80%. The best locality of all, Squantum 
Head, gives a percentage of 93%. A further search for striated 
pebbles by the blasting method would probably raise these percentages 
materially. So far nothing but geological hammers and chisels have 
been used. The striated rock-floor or pavement is entirely wanting. 
There is no prospect of finding this on account of the nature of the 
beds underlying the tillite. 
Locality 12. Squantum Southeast:— A,B,C,D,E,F,H,J,K,L,M,N,O. 
os 13. Squantum Head :— A,B,C,D,E,F,G,H,J,K,L,M,N,O. 
* 3. Roslindale:— A,B,C,D,F,G,H,J,K,L,M. 
4 1. Hyde Park:— A,B,C,D,E,F,G,H,J,K,L,M. 
is 10. Atlantic:— A,B,C,D,F,H,J,K,L,M. 
* 5. So. Forest Hills:— ALB: C.D, JA. 
~ 9. Franklin Field:— A,B,C,D,E,F,G,H,J,K,L. 
m 11. Atlantic-Squantum Kn:—A,B,C,D,J,K,L,M. 
' 17. Huit’s Cove:— A,B,C,D,F,J,L,M,N,O. 
“16. Moon Island :— A,B,C,D,J,K,L. 
* 8. Morton St:— A,B,C,D,F,H,J,L,M. 
6. Forest Hills Cemetery :— A,B,C,D,J,L,M,O. 
2. Milton Upper Mills— A,B,C,D,F,J,L. 
4. Roslindale:— MBG) dvb 
7. New Calgary Cemetery :—A,B,C,D,J. 
In view of the sum total of the evidence found in these different 
localities, I am forced to the opinion that there is true tillite in the 
Boston Basin. No other theory explains the evidence so far brought 
to light. 
DOUBTFUL LOCALITIES. 
About 500 feet northwest of Canterbury Street on Morton Street 
southeast of Forest Hills Cemetery, there is a conglomerate outcrop. 
In an open field 300 yards south of Walkhill Street and one fourth 
of a mile southeast of Harvard Street there is an outcrop of slate, 
sandstone, and perhaps tillite. 
