  We have imaged 8C 1435+635 (z=4.25; Lacy et al. 1994; Spinrad, Dey & Graham
1995) and 6C 0140+326 (z=4.41; Rawlings et al. 1996) in both continuum and
Lyalpha plus continuum bands with the HST. Our images show patchy distributions
of continuum and line emission with a tendency for the peaks in the two types
of emission to be offset. When compared to Keck K-band images, it seems likely
that the presence of dusty neutral gas is strongly influencing the UV continuum
and Lyalpha emission. The radio and UV emission are not particularly
well-correlated, except for a general tendency towards radio-optical alignment.
It is suggested that at least some of the observed radio-optical alignment is
produced as dust is cleared from the radio lobes by shocks associated by the
radio source. If true, this means that 8C1435+635 could be hosting a luminous,
galaxy-scale starburst, as suggested by submm observations.
