FOSSIL FISHES. 41 



FISHES OF THE CARBONIFEROUS SYSTEM. 



MARSIPOBRANCHII (?) 

 " CONOJDONTSr 



Plate LVII. 



In tlie first vohune of this Report reference was made in several places 

 to certain minute, comb-like or tootli-like organs, found in great numbers 

 in the Cleveland sliale of the Waverlj group at Bedford, Cuyahoga 

 county. They are from one-twentieth to one-fourtli of an inch in length, 

 and 'usually consist of a narrow, compressed, slightly arched base, from 

 which spring numerous flattened denticles. Tliese are generally long 

 lance-shaped, and very acute at the mai'gins and summits (see Figs. 1, 2, 

 12, 14, 16, 18, 19, 20). 



Occasionally they are in part rounded and obtuse (Figs. 3, 9, 10, 15), 

 but much oftener are acute and somewhat subulate. A not uncommon 

 form is represented l3y Figs. 4 and 8, In this variety the base is elon- 

 gated and narrow, in a few cases rod-like, and but slightly curved. From 

 this base rises a series of denticles of nearly uniform size, connected by 

 coalejcing intermediate ones of two-thirds their height; the whole form- 

 ing a fin-like margin or wing. Still another variety is seen in Fig. 1. 

 In this the teeth are fine and closely approximated, and the organ has a 

 wonderful likeness to an elongated comb. 



The material of which the Conodonts are composed, is slightly translu- 

 cent, horn-like in color, and closely resembles the enamel of many teeth. 



The number of these objects is immense, and the variety of form 

 which they exhibit, is but imperfectly shown in the figures now given. 

 In regard to their zoological relations it is as yet quite impossible to 

 speak Avitli certainty. The Conodonts found by Prof. Pander in the 

 Lower Silurian marls of St. Petersburg, Pussia, M-ere considered by him 

 to be the teeth of small sharks. This conclusion has not been generally 

 accepted by other palaeontologists, though no perfectly satisfactory expla- 

 nation of their zoological relations has been ofi^ered. Prof. Owen (Palae- 

 ontology, p. 116), discusses their structure and affinities at considerable 

 length, and concludes that " they have most analogy with the spines, 

 booklets, or denticles of naked molhisks, or annelids." 



