The possibility that tidal dissipation in a thin ice crust was sufficient to preserve liquid water on Jupiter's satellite Europa was suggested by Cassen et al, [1979>. However, their calculation of the tidal heating rate for this situation is in error. For the same parameter values, the actual heating rate would be much less than that given in the cited paper. Thus, their conclusion regarding the possibility that liquid water exists today on Europa is considerably weakened. The purposes of this paper are to correct the calculation of the tidal dissipation rate in a Europan ice crust, to discuss briefly the implications for Europa's thermal history, and to clarify certain aspects of the tidal heating problem which should have been obvious to the authors of the original paper.