DEVONIC FISHES OF THE NEW YORK FORMATIONS 57 



Cladoselache sp. ind. 



Plate 8, figure i 



The few species of Cladoselache that are known have been found 

 only in the Cleveland shale (Upper Devonic) and Waverly (Lower Car- 

 bonic) of Ohio. This statement is made, however, without taking into 

 account the numerous teeth known as Cladodus, some of which may possi- 

 bly belong to the Pleuropterygii. Under these circumstances it is interest- 

 ing to note the undoubted occurrence of the genus in the Portage beds of 

 western New York, as indicated by a well preserved pectoral fin belonging 

 to the Buffalo Society of Natural Sciences. This was obtained a few years 

 ago by Mr F. K. Mixer, of Buffalo, from a concretion in the Naples shale 

 of Eighteen Mile creek, near the shore of Lake Erie, and was by him sub- 

 mitted to the present writer for examination. Later it was placed in the 

 hands of Dr Dean for study, who has promised a more detailed description 

 of it in connection with newly discovered Ohio material. We may there- 

 fore content ourselves at present with a mere indication of the occurrence 

 of Cladoselache in a new horizon and locality, and with remarking upon the 

 decidedly primitive condition of the fin. This is indicated by its acutely 

 triangular, almost spinelike form together with the lack of crowding and 

 concentration of the numerous rays. The apex is more acutely pointed 

 than in any form hitherto described, and the radials, upwards of 70 in num- 

 ber, apparently extend inside the body wall. Characters of this nature are 

 regarded by Dean ' as suggestive of Acanthodian affinities, but it appears 

 tolerably certain that the two types of fins can have but a very remote 

 connection. The reasons for the latter view are thus stated by Dr A. S. 

 Woodward : ^ 



In conclusion, one word of protest against the American idea that the 

 paired fins of Cladoselache can be compared with those of an Acanthodian. 

 We venture to maintain that these fins are fundamentally different in every 

 respect. In Cladoselache the cartilages of the internal skeleton are well 

 developed and support the whole fin membrane ; in Acanthodians, what- 



' The Fin-fold Origin of the Paired Limbs, in the Light of the Ptychopterygia of 

 Palaeozoic Sharks. Anatom. Anzeig. 1896. 11: 678. 



= The Problem of the Primeval Sharks. Nat. Sci. 1895. 6: 42. 



