918 LAWS OF MARYLAND. [CH. 768

(A) Service performed in the employ of this State or
of any other State, or of any political sub-division thereof,
or any instrumentality of any one or more of the foregoing
which is wholly owned by this State or by one or more
States or political sub-divisions; and any service performed
in the employ of any instrumentality of this State, or of
one or more States or political sub-divisions to the extent
that the instrumentality is, with respect to such service,
exempt under the Constitution of the United States from
the tax imposed by Section 1600 of the Federal Internal
Revenue Code;

(B) Service performed in the employ of the United
States government or an instrumentality of the United
States exempt under the Constitution of the United States
from the contributions imposed by this Act, except that
to the extent that the Congress of the United States shall
permit States to require any instrumentalities of the United
States to make payments into an unemployment fund under
a State unemployment compensation act, all of the provi-
sions of this Act shall be applicable to such instrumentali-
ties and to services performed for such instrumentalities,
in the same manner, to the same extent and on the same
terms as to all other employers, employing units, indi-
viduals and services; provided that if this State shall not
be certified for any year by the Social Security Board
under Section 1603 (c) of the Federal Internal Revenue
Code, the payments required of such instrumentalities with
respect to such year shall be refunded by the Board from
the fund in the same manner and within the same period
as is provided in Section 14 (b) of this Act with respect
to contributions erroneously collected.

(C) Service performed after June 30, 1939, for an em-
ployer determined to be subject to the Railroad Unemploy-
ment Insurance Act by the agency or agencies empowered
to make such determination by an Act of Congress and
service as an employee representative determined to be
subject to said Act by said agency or agencies (except that
in the case of a company or person determined by the Rail-
road Retirement Board to be principally engaged in busi-
ness other than carrier business, this exclusion shall apply
to service for such identifiable and separable enterprise
conducted by that company or person as the said Board has
determined to be considered the employer); and service
for an employer who is determined to be subject to any
other unemployment compensation system established by
an Act of Congress by the agency or agencies of the United
States empowered to make such determinations.