192 AL^ONTOLOGY OF KENTUCKY. 



tusely angular carina, which is continued from the suture-line at the inner 

 posterior angle of the aperture. The outer one or two of the volutions (de- 

 pending on the size of the shell) are marked or ornamented by strong curving 

 nodes, which, commencing just below the suture, are nearly vertical for a short 

 distance, and then curving forward, are finally directed towards the aperture, 

 and gradually become merged into the general surface. 



The striae, originating at the suture, are first directed backward, and thence, 

 gently curving over the nodes, become nearly vertical, and thus continue to 

 near the peripheral carina, where they are turned a little backward, and, pass- 

 ing this elevation, they are directed with a light curve towards the coin- 

 mella. 



This species possesses all the features of the Linnaean genus Turbo, to which 

 it was originally referred by M. de Verneuil, who described and named it in 

 honor of the late Prof. B. F. Shumard, of St. Louis. It is so very different 

 from all other shells of our rocks, that it will be recognized at the first glance 

 by any one, who has ever seen a correct illustration of it. The shell is usually 

 silicified, and is rarely well preserved or occurs as internal casts, which bear 

 only slight indications of the nodes, but none of the other surface-ornamenta- 

 tions. 



Prof. Hall made his descriptions and illustrations from fine specimens be- 

 longing to the cabinet of the late Dr. James Knapp. One of Knapp's speci- 

 mens was also used for my illustrations, sub-figures 1, 2 and 3, plate 19. The 

 individual, of which figure 4, plate 19, and figure 2, plate 22, are copies, is in 

 my own collection, presented to me by Miss Spangler, of Clark county, Indi- 

 ana. 



Formation and Locality Found in the rotten hornstone of the Devonian formation in Jefferson 

 county, Ky., and in Clark county, Ind. It is not a very rare species, although specimens like Dr. Knapp's 

 and my own are extremely rare. 



