The Tertiary and Quaternary pectens of California

This paper consists of two parts. The first is a brief outline of the different Tertiary and Pleistocene formations of California, giving the type localities, where, when, and by whom first described, their salient characters, where they and their supposed equiyalents are known to occur, the species of Pecten found in them, and their typical fauna as far as known. The second is devoted to the description and illustration of all of the known Tertiary, Pleistocene, and Recent Pectens of the western coast of North America from Alaska to and including the Gulf of California. With the description of each species is also given an account of its geologic and geographic range and, where practicable, its associated fauna.