The crystal structure of a paraffin binary eutectic formed from a nearly 1:1 combination of n-C30H62/n-C40H82 was determined with electron diffraction intensities from epitaxially oriented microareas. A pure n-C40H82 component could be isolated. and its diffraction pattern could be shown to match the structure expected for the pure even-chain paraffin in the Pca2(1) orthorhombic crystal structure. Although the microarea itself could not be isolated in electron diffraction experiments, the superlattice component of the lamellar row was separated from that of the pure longer chain species. After assigning a crystallographic phase envelope to these reflections to calculate the reverse Fourier transform, the sequence of lamellae suggested a packing model of pure components similar to the one found earlier for the n-C30H62/n-C36H74 binaries. The packing model also agreed well with the observed intensity data, given the suggested separation of the observed diffraction component from the overlapped patterns.