Photometry of type II Cepheids. III. The intermediate-period stars

We present 741 new photometric observations for 22 Cepheids with periods between 3 and 8 days. Many of the stars are probable type II Cepheids, but we have included some type I Cepheids for comparison. The shapes and stability of the shapes of the light curves, the stability of the periods, and the scatter of individual data points are discussed. Although none of these proves to be a reliable discriminator between type I and type II Cepheids, they do permit the identification of several unusual stars.