A catalogue of 25 supernova remnants is presented. It is probably free of spurious objects. The objects are shown to satisfy a relation between radio surface brightness at 400 Mc/sec and radius with quite small scatter. On the basis of this relation, distances can be determined. The accuracy of these distances is sufficient to show that the supernova remnants delineate local spiral structure as clearly as do young galactic clusters. Evidence is presented that remants in the galactic halo expand faster than those in the disk. Because of this our sample contains mainly Type II supernova remnants. Ten positional coincidences to within 25 be- tween supernova remnants and x-ray sources are noted in a sample where less than two random coincidences are expected. The x-ray emission appears to be correlated with age, declining more slowly than the radio emission in the early phases. The relation between surface brightness and radius does not satisfy Shklovsky's theory. A possible explanation of the observed relation is given. The optical spectra of the remnants are discussed and the inadequacy of the usual treatment of collisional excitation is noted. The energies of some remnants are evaluated and are below 5 X 10 ergs. In the litei ature the energies released in Type II super- nova outbursts are sometimes given as of the order of 10 ergs. It is shown that neither the supernova remnants nor the supernova spectra indicate the release of so much energy. We conclude that there is no evidence that supernovae of Type II are catastrophic events related to ultimate stellar collapse.