  Tangled, primordial cosmic magnetic fields create small rotational velocity
perturbations on the last scattering surface (LSS) of the cosmic microwave
background radiation (CMBR). For fields which redshift to a present value of
$B_0 = 3\times 10^{-9}$ Gauss, these vector modes are shown to generate
polarization anisotropies of order $0.1\mu K - 4 \mu K$ on small angular scales
($ 500 < l < 2000$), assuming delta function or a power law spectra with
$n=-1$. About 200 times larger signals result for $n=2$ spectra. Unlike
inflation generated, scalar modes, these signals are dominated by the odd
parity, B-type polarization, which could help in their detection.
