For three supernova remnants in the Large Magellanic Cloud, N86, N186D, and N206, monochromatic plates are used to compare the structure in a line of high excitation, [O III] \5007, with that in lines of low excitation, [S n] M6716, 6731. The images in [O ill] as compared to [S n] tend to be concentrated toward the periphery of the remnants (N86, N186D, and N206), to be sharper (N86, N186D), to lie outside the peak of the [S n] emission (N206), and perhaps to have less prominent filamentary structure (N86).Explanations are suggested in terms of the structures of the regions associated with the shock waves.