Several new species of Amphora and Halamphora from the western USA

Amphora Ehrenberg ex Kutzing sensu lato incorporates a large and diverse group of diatoms. Although having its greatest taxonomic diversity in marine environments, inland waters of the USA appear to hold a large amount of undescribed taxa diversity requiring thorough taxonomic investigation. Presented here are descriptions and illustrations of seven new species collected from inland waters of the western USA, based on light and scanning electron microscope observations. Species described include A. copulatoides, A. manifesta and A. waldeniana from the genus Amphora subgenus Amphora and H. coloradiana, H. latecostata, H. punctata and H. subtilis from the genus Halamphora (Cleve) Levkov. This work represents the first steps in a larger taxonomic and systematic investigation into Amphora sensu lato from inland waters of the USA.