DEVONIAN FISHES OF IOWA 225 



labial cartilage known as Ganorhynchus beecheri, all of which 

 very possibly pertain to one and the same species- Somewhat 

 similar calcified bodies of the "Ganorhynchus" type occur in 

 the Cedar Valley limestone near Waverly, Iowa, in the Middle 

 Devonian of the Eifel District, and in the Murrumbidgee De- 

 vonian limestone of New South Wales. One excellent example 

 from the Australian locality has been described by E. Etheridge, 

 Jr., in natural position with the head shield, the plates of which 

 are arranged in much the same fashion as in the Canadian 

 genus Scaumenacia.* 



Formation and locality. Chemung beds; "Warren county, 

 Pennsylvania, and Alleghany county, New York. Probably an 

 immigrant from the Upper Devonian "Dakotan Sea". 



Dipterus fleischeri (Newberry). 



(Plate II, Fig. 16) 



1897. Ctenodus fleischeri J. S. Newberry, Trans. N. Y. Acad. Sci. 16, p. 302, 

 pi. 24, fig. 25. 



1907. Dipterus fleischeri C. R. Eastman, Mem. N. Y. State Museum, 10, p. 



162, pi. 7, fig. 2. 



1908. Dipterus fleischeri L. Hussakof, Bull. Amer. Mus. Nat. Hist. 25, p. 52. 



Upper dental plates thin, slightly concave, triangular in out- 

 line; coronal surface traversed by six rows of rounded obtuse 

 tubercles increasing in size from the posterior angle outwards. 

 At least the anterior or innermost rows of tubercles are con- 

 tinuous almost to the postero-internal angle. 



Besides the type, only one other example of this species has 

 yet been brought to light. This is a large upper dental plate, 

 preserved in counterpart, now the property of the New York 

 State Museum. It is from the Catskill of Delaware county, New 

 York, and being more complete than Newberry's original, we 

 present a figure of it herewith. Its relations are evidently with 

 D. uddeni and D. mordax, as shown by the small number of 

 coarsely tuberculated costae; but in size it is much larger, the 

 length of the inner margin being fully 5 cm. 



* Etheridge, Jr., R., The cranial buckler of a Dipnoan fish, probably Ganorhyn- 

 chus, from the Devonian beds of the Murrumbidgee River, New South Waies. 

 Rec. Austral. Museum, 1906, 6, no. pp. 129-132, pi. 28. 



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