270 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



sheath enveloped the immediately preceding segment. A specimen 

 closely rivalling the one here figured in size and perfection of preserva- 

 tion, hut showing a series of nine teeth instead of ten, has recently 

 been acquired by the American Museum of Natural History. 



TELEOSTOMI. 

 Order CROSSOPTERYGII. 



The larger number of remains of "fringe-finned ganoids" belong- 

 ing to the United States National Museum collection consists of Rhizo- 

 dont scales (14 of them being types described by Cope and others), 

 small Coelacanths, and more or less complete skeletons of Palaeoni- 

 scids, all preserved within concretions from the well-known Mazon 

 Creek locality m Grundy Comity, Illinois. Most of these nodules 

 were formerly contained hi the Lacoe collection, acquired by 

 the Museum about twenty years ago. The Lesquereux collection 

 was especially rich m fossils from the Coal Measures of Linton, Ohio, 

 and most of the fishes from this locaUty are Coelacanths. The so- 

 called ichthyic genus and species, Myderoys orcinatus Cope ^ from 

 the Coal Measures of Beaver County, Pennsylvania, is not of verte- 

 brate nature, but founded upon arachnid fragments. The type is 

 catalogued as No. 1977, and another specimen identified as a jugular 

 plate of Coelacaiithus by Jaekel, is catalogued as No. 1975. 



Family COELACANTHIDAE. 



Genus COELACANTHUS Agassiz. 



The earliest known representative of this genus is a small form 

 occurrmg in the basal member of the Upper Devonian near Gerol- 

 stem, in Rhenish Prussia, first described by the late Prof. A. von 

 Koenen^ m 1895, and recognized as a true Coelacanth by Smith 

 Woodward^ in 1898. A single species, C. weUeri, has been described 

 by the present writer from the base of the Kinderhook limestone near 

 Burlington, Iowa, and two species of this and a pecuhar allied genus, 

 PalaeophicJithys, have been made laiown from remams preserved in 

 nodules found at the famous Mazon Creek locaUty in lUinois. 



In the Palaeontology of Ohio (vol. 1, 1873) twenty-seven species of 

 fossil fishes are described from the Coal Measures of Linton, Ohio, 

 and among the number are three belonging to the genus Coelacanthus. 

 It is stated by Newberry * that the second most abundant species 



' Amer. Naturalist, vol. 20, 1886, p. 1029. 



2Koenen, A. von. Ueber einige Fischreste dos norddeutschen und bohmischen Devons. Abhandl. 

 Ges. Wiss. Gottingen, phys. 01., vol. 40, 1S95, p. 28. 



3 Woodward, A. S. Note on a Devonian Coelacanth fish. Geol. Mag., vol. 5, 1898, p. 529. 



* Newberry, J. S. The Paleozoic Fishes of North America, Monogr. U. S. Geol. Survey, vol. 16, 1889, 

 p. 213. 



