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In centrosymmetric chromophores, such as linear polyees, approximately half of the electronic excited state manifold is inaccessible from the ground state by conventional absorption spectroscopy because of parity selection rules. However, the presence of such hidden'' excited states can sometimes be inferred from preresonance Raman excitation profiles. As the excitation radiation is tuned through the appropriate energy range, vibronic coupling between the state of interest and nearby allowed'' electronic States will produce interference effects in the ground state scattering intensity. Thrash, $etal.1$ used this method to determine the approximate origin of the lowest lying excited gerade single state $(1Ag\ast$) of $\beta$-carotene, preresonant with the neighboring higher-energy $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}Bu\ast$ state. We have reexamined the preresonance Raman excitation profile of $\beta$-carotene, using improved instrumentation and a careful statistical analysis. Excitation was supplied by an Ar-pumped tunable dye laser in the wavelength regions covered by rhodamine 560 and coumarin 540. The excitation spectrum was determined point-by-point from the ratio of the scattered intensity of the $\beta$-carotene C---C stretch ($1525cm-1$) to that cyclohexane solvent made at $1450cm-1$. The interference pattern observed previously is generally confirmed; however, inherent experimental uncertainlee limit the inferences which may be drawn from such excitation profiles. The technique has been applied to other linear polyenes, and results for all systems investigated to date will be described.