Additional bus companies, listed as existing during 1930's, are mentioned in the WPA American Guide Series of state guidebooks.
Ipswich Bus Line - city service in Ipswich.
MacDonald Bros. - served Ipswich and Rowley.
Mason's Bus Line - existed in 1930's.
Northeastern Bus Line - existed in 1930's.
Boutin's Bus Lines - served Newbury and Newburyport.