Benthic foraminifera of the Panamanian Province: distribution and origins.

Two hundred twenty-nine species of benthic foraminifera have been identified from 96 stations representing 33 localities on the eastern Pacific inner continental shelf, ranging from southern Peru to northern Baja California. Their distributions mark nearshore provincial boundaries that are nearly identical with those previously documented from the distribution of ostracodes and molluscs. Thirteen species are characteristic of the Panamanian Province, one is characteristic of the Chilean-Peruvian Province, and one is characteristic of the newly proposed Sonoran Subprovince. Seventeen species (7%) appear to be endemic to the eastern Pacific. Fifty-eight (25%) of the species recognized are disjunct from population centers in the western Pacific, 134 species (59%) are disjunct from modern assemblages of the Atlanto-Caribbean region, and 40 species (17%) are disjunct from both the western Pacific and the Atlanto-Caribbean. The distribution of the remaining 57 species (25%) is poorly documented; we classify them as of unknown origin.