HERBERT R. O'CONOR, GOVERNOR. 587

(5) Notwithstanding anything to the contrary in this Act,
membership in the retirement system shall be optional with
any class of elected officials, or with any class of officials ap-
pointed for fixed terms.

(6) Should any member in any period of six consecutive
years after last becoming a member be absent from service
more than two years, or should he withdraw all or part of his
accumulated contributions, or should he become a beneficiary
or die, he shall thereupon cease to be a member.

(7) It shall be the duty of the head of each department to
submit to the Board of Trustees a statement showing the
name, title, compensation, duties, date of birth, and length of
service of each member and such information regarding other
employees in his department as the Board of Trustees may
require. The Board of Trustees shall then place each member
in one of the following groups:

Group 1. Clerical, administrative, professional and tech-
nical workers engaged in duties requiring principally mental
exertion.

Group 2. Laborers, mechanics and other workers engaged
in duties requiring principally physical exertion.

Any other group of not less than two hundred and fifty per-
sons which may be hereafter recommended by the actuary on
the basis of service and mortality experience and approved by
the Board of Trustees, to cover all or part of any group or
groups previously created or any additional classes of em-
ployees.

4. Creditable Service. (1) Under such rules and regula-
tions as the Board of Trustees shall adopt each member who
was an employee at any time during the year immediately
preceding the date of establishment and who become a mem-
ber during" the first year after the date of establishment, shall
file a detailed statement of all service as an employee rendered
by him prior to the date of establishment for which he claims
credit.

(2) The Board of Trustees shall fix and determine by ap-
propriate rules and regulations how much service in any year
is equivalent to one year of service, but in no case shall it
allow credit for a period of absence without pay of more than
a month's duration nor shall more than one year of service
be creditable for all service in one calendar year. Service
rendered for the full normal working time in any year shall
be equivalent to one year's service.

(3) Subject to the above restrictions and to such other
rules and regulations as the Board of Trustees may adopt,
the Board of Trustees shall verify, as soon as practicable after
the filing of such statements of service, the service therein
claimed.