ON AN IMPORTANT SPECIMEN OF EDESTUS; WITH 

 DESCRIPTION OF A NEW SPECIES, EDESTUS MIRUS. 



By Oliver Perry Hay, 

 Research Associate of the Carnegie Institution of Washington. 



The fine specimen of Edestus here described, and now the property 

 of the United States National Museum (Cat. No. 7255), was dis- 

 covered about 18 years ago by a miner of coal at Lehigh, Webster 

 County, Iowa. Through the intelligent interest of Mr. R. A. Peterson, 

 of Leliigh, the specimen was recently sent to the United States 

 National Museum for examination, and for this purpose it was 

 ])laced*in the hands of the writer. From correspondence with Mr. 

 Peterson it has been learned that the remains were discovered in the 

 black shale which overlies the bed of coal that is locally known as the 

 Tyson seam, and at a depth of 165 feet from the surface. From the 

 coal the specimen was separated by a thin layer of sandstone. Further 

 remarks on the geological position of this coal vdW. be made below. 



The specimen so fortunately discovered represents apparently a 

 species hitherto unknown; but what is of still greater importance is 

 the fact that it appears to explain the relation of the objects known by 

 the name of Edestus to the body of the animal that bore them, and 

 we can hardly doubt that the same explanation will apply to the 

 still more remarkable objects known as Toxoprion, Helico prion, and 

 Lissoprion. Among those who have occupied themselves in the 

 study of the straight, or bent, or coiled structures wliich bear the 

 names mentioned, there has been much dispute regarding the position 

 which they had in the body, especially as to whether they belonged 

 in the mouth or in the neighborhood of some of the fins. In a paper 

 published not long ago * the writer advocated the proposition that 

 the toothed shafts of Edestus and even tlie toothed whorls of Ilcli- 

 coprion had been produced in front of some of the mecjian fins of 

 sharklike animals. In the presence of the specimen here described 

 this fine theory vanishes, for the remains seem to indicate distinctly 

 that the tooth-bearing shafts of Edestus belonged to the region of the 

 mouth and nowhere else. 



> Proc. U. 8. Nat. Mus., 1909, vol. 37, pp. 4»-61. 



Proceedings U. S. National Museum, Vol. 42-No. 1884. 



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