Sources of Massachusetts town names

I was talking with my mother and sister the other day about, how many towns in Massachusetts have indigenous names? And the answer seemed to be... not very many, but I wasn't sure. So I went ahead and made this map, and it looks like the answer is... about 15 out of 351 towns in Massachusetts have names derived from indigenous Algonquian languages. Most of the town names in Massachusetts come from England.

Take the accuracy of this map with a grain of salt; I did very haphazard research to create it, mostly on Wikipedia and town history websites, with a lot of educated guessing. But here it is, in case you're interested:



Below are some more detailed notes and examples of what the colors mean:
( Details and examples )