Mass. Gen. Laws ch. 36 § 33
The salaries of registers of deeds and all assistant registers of deeds shall be paid by their respective counties; and the salaries of registers of deeds shall be in full for all services rendered as register and as assistant recorder of the land court.
The salaries of the register of deeds for the county of Suffolk, and his assistants shall be as follows:--
Register: A sum equivalent to seventy-five per cent of the salary of an associate justice of the superior court.
First assistant register: A sum equivalent to the salary of the first assistant clerk of the superior court department for civil business in the county of Suffolk.
All other assistant registers: A sum equivalent to the salaries of the assistant clerks of the superior court department for civil business in the county of Suffolk.
Mass. Gen. Laws ch. 36, § 33