A new Subemarginula from California / by William Healey Dall. Observations on Unio giganteus Barnes / by L.S. Frierson. Pleistocene Mollusca from Callaway county, Missouri / by Darling K. Greger. The feeding habits of Busycon / by Shields Warren. Descriptions of new species from the Cretaceous and Tertiary of the Tesla, Pleasanton, San Jose, and Mt. Hamilton Quadrangles, California / by E.B. Hall and A.W. Ambrose