Collected from near Sharonville, Ohio...I think Devonian... by a friend...is this a Cystiphylloides americanum? Approx. 1 3/4" x 1 1/2". The reason I ask...is I only have books from Devonian of NYS. This is the first fossil shaped like a horn coral with this outside pattern that I've seen. The one horn coral in my book that has this patterning is long and slender...while this is short and fat.
Greg