Spectra of over 100 stars classed as type II Cepheids of short period (BL Her-type) or long period (W Vir-type) or RV Tauri stars have been obtained. A range of metallic line strength and hence presumably metal abundance is present at all periods, those having weak lines being found especially in the globular clusters and the central bulge of the Galaxy. Stars which have enhanced Carbon molecular features (CH, CN and sometimes C2) occur at all periods but are probably distributed differently in space from the other stars.