The Charles River canoe was the topic of the 2007 WCHA Assembly. It's as you suggested: a type of canoe rather than a canoe by a specific builder, although Old Town made a model called the Charles River.
The Charles River became a hot-spot for canoeing in the early years of the 20th century. There were many canoe-builders along the Charles... and there were places to rent or store a canoe. Prior to the use of the automobile as a courting-tool, the canoe was considered a very romantic way for a young man to show his appreciation for a lady. This is why the canoe-type popularized by the Charles River builders is also called "a courting canoe".
Courting canoes-- and those by Charles River builders in particular-- are characterized by long decks--- 3 feet or more-- "torpedo" ends-- and lots of mahogany trim (or another fancy wood species, like bird's eye maple). Most courting canoes sported fancy paint-designs.
The canoes were usually stuffed with pillows for comfort and Victrola to serenade the lady... a picnic lunch... and rules of propriety (this was Boston, after all) such as "all persons must be visible above the gunwales".
You may want to use the "search" function above to find some cool pictures...
Kathy
