Descriptions and illustrations of smaller Foraminifera from the Gulf Coastal region, Cuba, Central America, Haiti, and Trinidad.

Describes an extraordinary endemic radiation of hydrobioid snails in the Mekong River (MR). The monophyletic radiation involving the subfamily Triculinae, 3 tribes, 11 genera, & 92 species, is larger than contemporaneous endemic freshwater gastropod faunas of centers of endemism, such as lakes Tanganyika & Baikal. The study addresses the issue of how higher taxa arise by analyzing the series of adaptive radiations within the MR Triculinae. The worldwide family Hydrobiidae is polyphyletic & includes 2 distinct lineages, the Hydrobiidae sensu stricto & the Pomatiopsidae with the subfamilies Pomatiopsidae & Triculinae. The differences between the two families were masked by convergence in shell, radula, penis, & operculum. Maps & illus.

A description of the stratigraphy, structure, and surficial deposits in a 15-minute quadrangle that includes the meizoseismal area of the Hebgen Lake earthquake of August 17, 1959.