[Ne v] imaging of the Cygnus Loop

We present continuum-subtracted images of a 20' x 20' region of the eastern Cygnus Loop (NGC 6995) in the 3425 Angstrom forbidden line of Ne v. The images reveal bright linear filaments which are associated with, but not positionally coincident with, bright features seen in H alpha, [O III], and other narrowband images. In some areas, the [Ne v] filaments define the edge of X-ray-emitting regions. The filaments exhibit a peak surface brightness of 1.2 x 10(-4) photons cm(-2) s(-1) arcsec(-2) at the top of the atmosphere in images with typical detection limits of similar to 10(-5) photons cm(-2) s(-1) arcsec(-2). We present arguments that these structures are produced by radiative shock waves and discuss implications for the shock velocities and the three-dimensional structure of this section of the Cygnus Loop. We place limits on the importance of thermal conduction-driven evaporation as a contribution to the mass of X-ray-emitting gas. Lack of evidence of [Ne v] emission resulting from thermal evaporation may have significance for supernova remnants and interstellar medium models that rely heavily on the importance of thermal evaporation.