Six new EPR spectra are reported which are apparently due to intrinsic defects created in the neutron-irraditation and, in some cases, annealing of silicon. In addition a spectrum similar to, but distinct from, that due to the vacancy-phosphorus center is reported. Some tentative defect models are discussed to emphasize the features of the spectra, but more detailed studies are required to establish the identity of the defects giving rise to these spectra.