A number of strong P-coda phases have been observed on European WWSSN-station short-period recordings of intermediate-magnitude, Kurile arc earthquakes which occurred at several different depths of focus. These phases have been observed for several different events and cannot be explained by known phases, such as PcP or source multiplicity. A lower-mantle model, containing a first-order discontinuity with a 2.75% P-wave velocity contrast and located about 344 km above the core-mantle boundary, produces synthetic seismograms which approximately reproduce the observed amplitudes and arrival times of the coda phases. However, the fact that these phases are not always observed and that their amplitudes vary significantly for different events and stations suggests that the discontinuity at the top of D' may be a transition zone and may be laterally variable in thickness and contrast. ¿ American Geophysical Union 1989