WM. PRESTON LANE, JR., GOVERNOR. 845

following the date of filing such application, on an ordinary
disability retirement allowance, provided that the Medical
Board, after a medical examination of such member, shall
certify that such member is mentally or physically incapaci-
tated for the further performance of duty, that such inca-
pacity is likely to be permanent, and that such member should
be retired for the good of the Department.

ALLOWANCE ON ORDINARY DISABILITY RETIREMENT

(4) Upon retirement for ordinary disability a member shall
receive a service retirement allowance if he has attained the
age of 55, otherwise he shall receive an ordinary disability
retirement allowance which shall consist of:

(a) An annuity which shall be the actuarial equivalent of
his accumulated contributions at the time of retirement; and

(b) A pension which, together with his annuity shall pro-
vide a total retirement allowance equal to ninety per centum
of one-fiftieth of his average final compensation for each of
the first twenty-five years of creditable service and one-six-
tieth of his average final compensation for each year after
the first twenty-five years of creditable service, if such
service retirement allowance exceeds one-quarter of his aver-
age final compensation; otherwise a pension which, together
with his annuity, shall provide a total retirement allowance
equal to one-quarter of his average final compensation, pro-
vided, however, that no such allowance shall exceed ninety
per centum of one-fiftieth of his average final compensation
for each year of creditable service were his service to continue
until the attainment of age 55.

SPECIAL DISABILITY BENEFIT

(5) Upon the application of a member in service, or of the
head of his department, any member who has been totally and
permanently incapacitated for duty arising out of or in the
course of the actual performance of duty, without wilful
negligence on his part, shall be retired by the Board of Trus-
tees, provided that the Medical Board shall certify that such
member is mentally or physically incapacitated for the further
performance of duty, that such incapacity is likely to be
permanent, that such incapacity arose out of or was sustained
in the course of the actual performance of duty without
wilful negligence on the part of the member concerned, and
that such member should be retired. No beneficiary entitled
to a special disability retirement allowance shall receive any
allowance on account of ordinary disability.