Yet another sub-component inside a bulge: the structure of the peculiar S0 galaxy NGC3384.

This new investigation of the structure of NGC3384 - the multi-component lenticular galaxy member of the Leo Triplet - is based on CCD frames in the BVR bands, on deep Schmidt plates and on long slit spectra. Besides the already known elongated component along the photometric minor axis, the application of an adaptive filter to a NTT CCD image of the galaxy, and the behaviour of the color light profiles, have revealed the existence of a small (r~6"=~300pc) central component aligned to the disk major axis. The shape of the stellar rotation curves and of the velocity dispersion profiles seem also due to the presence of such inner component, which can be a small disk or a secondary bar. After removal of the contamination by the nearby galaxy NGC3379, the light distribution of NGC3384 shows a residual asymmetry (~0.1mag) in the intermediate and outer regions which cannot be attributed to diffuse dust and implies a non axisymmetric distribution of the stars in the disk. The observed asymmetries can be interpreted as a relic of the Spitzer-Baade event which took place about 5x10^8^yr ago between NGC3384 and NGC3368, and which is invoked to explain the large intergalactic HI cloud observed in the Leo region.