Evolution of indigenous Alaskan pectinid stocks, of migrant stocks from other areas in the Pacific region, and of boreal Pacific species that subsequently migrated to the Arctic and northern Atlantic regions.

Scientific notes and summaries of investigations in geology, hydrology, and related fields.

Thirty-nine taxa, many of them index species, are described and illustrated; their biostratigraphic and chronostratigraphic significance are related to tectnostratigraphic settings.