"Officer", an officer of the department of state police appointed thereto under section ten of chapter twenty-two C.
"Rating board", a board having the powers and duties provided for in this section, and consisting of the state surgeon, the commissioner of public health, the colonel of state police, or a subordinate designated by any of them from time to time by a writing filed in the office of the state board of retirement.
Mass. Gen. Laws ch. 32, § 26