It would be easy to conclude that these letters are lower-case “t”s with a cross. They are not.
The image above is a summary of the grantor/grantee information for those using the record copy of the deed. The actual deed record, shown partially in the image below clearly indicates that the first names of both men were intended to be William.
This image comes from FamilySearch‘s “Massachusetts, Land Records, 1620-1986” and is actually from Middlesex County Deeds vol 1, pp. 170-171.
The lines on the names are meant to indicate that letters have been omitted.