This paper will aim to do for one genus of Paleozoic corals what is much needed for many others; it will attempt to give definiteness to the set of characters by which the genus may be recognized, will examine the various species assigned to it with reference to these characters, and will indicate the special points of structure by which it may be distinguished from its nearest relatives.
The work was begun upon the suggestion and under the direction of the late lamented Dr. Alexander Winchell, with the freedom of his valuable paleontological library.
In the first volume of his great work, published in 1826, the learned Goldfuss described and figured a simple decorticated coral from Kentucky as Cyathophyllum plicatum.* The septa are stated to be somewhat thickened, not converging regularly at the center, but folded and twisted. A few pages later, but in the same . . .