The Diatomaceæ of Philadelphia and Vicinity

A systematic regional survey of diatoms collected in and around Philadelphia and within about a one-hundred-mile radius, presenting species descriptions, habitat notes, fossil occurrences, and ecological observations. The author outlines local geology and hydrology, sampling locations (rivers, creeks, ponds, bays, wells, bogs), preparation and microscopic methods, and provides detailed species accounts illustrated by seven hundred uniformly scaled drawings. The text discusses freshwater, brackish, and marine forms, distribution patterns, seasonal and environmental influences on diatom growth, and the use of diatoms in water analysis, stratigraphy, and biological studies, aiming to support further research.