DEVONIAN FISHES OF IOWA 111 



general outlines and as regards absence of lateral denticles, the 

 new form presents some resemblance to C. pattersoni, from the 

 Waverly of Ohio. The latter, however, besides being from a 

 later horizon, differs from the present form in having the prin- 

 cipal cone strongly convex in cross-section, much reflexed and 

 sigmoidally curved at the apex, and smooth and polished 

 throughout. 



The holotype was collected many years ago by Mr. W. N. 

 Longworth, of Louisville, Kentucky, from whom it was obtained 

 in 1867, along with other remains from the same locality, by the 

 late Professor 0. C. Marsh. Through exchange with the Director 

 of the Peabody Museum at Yale, Professor Schuchert, it has be- 

 come the property of the Museum of Comparative Zoology. 



Formation and locality. New Albany or Genesee Black Shale 

 (a horizon just above the Hamilton) ; near Louisville, Kentucky. 



Cladodus springeri, exiguus, exilis, etc. 



Under the above names have been described several varieties 

 of Cladodont teeth whose relations are with typical Lower 

 Carboniferous species, although they are accompanied in the 

 same "fish-beds" of the Kinderhook limestone, near Burlington, 

 Iowa, by other vertebrate and numerous invertebrate species 

 of undoubted Devonian (Chemung) aspect. The dual nature of 

 the Kinderhook fauna has been clearly demonstrated by Dr. 

 Stuart Weller's recent investigations.* It will therefore be 

 sufficient merely to record the presence of the above-mentioned 

 Cladodonts as forming part of this complex assemblage, transi- 

 tional between Devonian and Carboniferous, but having pro- 

 nounced affinity with those later types of piercing teeth which 

 are specially characteristic of the Mississippian series. The 

 Belgian palaeontologist, L. de Koninck, has suggested that the 

 teeth named C. alternatus, succinctus and icachsmuthi are prob- 

 ably all identical with C. springeri, a conclusion that is fully 

 approved by Smith Woodward. A similar form of tooth occurs 



*Weller, S., The Northern and Southern Kinderhook Faunas. Journ. Geol. 



1905, 13, pp. 617-634. Kinderhook Fauna! Studies. Trans. Acad. Sci. St. Louis, 



1906, 16, no. 7. 



