- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Study of sections and by serial grinding indicates that fossils described by R. Rezak as new dasycladaceans from Silurian localities of the southwestern United States (Colorado School Mines, Quart. Vol. 54, p. 117-129, 1959) are portions of stems of crinoids resembling European species belonging to the Crotalocrinidae and the Polypeltidae.