  We have carried out a high-dispersion (R~30,000) echelle spectroscopic survey
of 16 Type II supernovae (SNe) to search for narrow emission lines from
circumstellar nebulae ejected by their massive progenitors. Circumstellar
nebulae, if detected, provide invaluable opportunities to probe SN progenitors.
Of the 16 SNe observed, SN ejecta are clearly detected in 4 SNe and possibly in
another 2 SNe, interstellar gas is detected in 12 SNe, and circumstellar
material is detected only in SN 1978K and SN 1998S. In the case of SN 1978K we
are able to place an upper limit of ~2.2 pc for the size of the circumstellar
ejecta nebula and note that this is more consistent with the typical sizes
observed for ejecta nebulae around luminous blue variables rather than
Wolf-Rayet stars. In the case of SN 1998S, our observations of the narrow lines
\~1 year after the SN explosion show variations compared to early epochs. The
nebular lines we observe from SN 1998S originate from either the low--density,
outer region of a circumstellar nebula or have become dominated by an
interstellar component.
