A contribution to the history of the Panamá land bridge.

A description of a method whereby geologic mapping and geochemical sampling are possible.

The culmination of a ten-year study, Bivalve Seashells of Western North America treats all bivalve mollusks living from northern Baja California, Mexico to Arctic Alaska. A total of 472 species are described and illustrated with detailed photographs and drawings. All habitats in the region are included from the intertidal splash zone to the abyssal depths of the ocean basins. The book has over 4,800 complete bibliographic references to the bivalves, including citations on the biology, physiology, ecology, and taxonomy of this commercially and biologically important group. Character tables and dichotomous keys assist the reader in identification. Also included in the 764 page book is an illustrated key to the superfamiles of the region, and a complete glossary.