DUCK POND, CORNER OF FOURTH AND MARKET STREETS (ABOUT 1700)
THE DIATOMACEÆ OF
PHILADELPHIA AND VICINITY
BY
CHARLES S. BOYER, A.M., F.R.M.S.
ILLUSTRATED WITH SEVEN HUNDRED
DRAWINGS BY THE AUTHOR
PRESS OF
J. B. LIPPINCOTT COMPANY
EAST WASHINGTON SQUARE PHILADELPHIA
1916