Ultrastructural Studies on Graptolites, 2: The Periderm and Its Derivatives in the Graptoloidea. Smithsonian Contributions to Paleontology Number 22.
Urbanek, Adam adn Kenneth M. Towe

Washington, DC:: Smithsonian Institution Press, 1975, 24pp + plates Wraps, very good. Ex. Lib (Item ID: 4355)

$10.00