Abstract
A study of the littoral ascidians of the mainland of southern California was conducted during the summer of 1970. The collecting sites are recorded and natural history notes on the 41 species listed are presented. The number of species found in each of the four areas studied along the coast (Santa Barbara. Ft. Dume, Palos Verdes-Los Angeles Harbor, and San Diego) suggests that the contemporary distribution of tunicates may be controlled more by water quality than by the availability of a physically suitable habitat.
