THE DEVONIAN FISHES OF MISSOURI 



E. B. BRANSON 



Professor of Geology 



Ptyctodus calceolus is the only fish that has previously 

 been reported from the Devonian of Missouri, but recently 

 several other species have come to the writer's attention and 

 they are described in the present paper. Most of these were 

 collected by Mr. R. R. Rowley in the vicinity of Louisiana, 

 but Mr. D. K. Greger has furnished remains of two species 

 from Callaway County, Mr. H. M. Scott one form from near 

 Providence, and the writer has collected a few specimens from 

 Louisiana, Callaway County, and Providence. A few speci- 

 mens from Louisiana are in the Walker Museum of the Univer- 

 sity of Chicago and some fragments from the same locality 

 were in the museum of the University of Missouri before the 

 present investigation was started. 



Mr. Rowley's collection consists of six species of elasmo- 

 branchs, represented by ten specimens, one species of chi- 

 maeroid, represented by some two hundred specimens, and 

 several species of arthrodires, represented by about one hun- 

 dred bones and fragments of bones. No two of these bones 

 are known to belong to the same species, but it is probable 

 that some of them belong to the same individual, and in the 

 descriptions given below the bones that seem to belong together 

 are described as representing one species. The groupings may, 

 in some cases, be incorrect, but it seems better to make them, thus 

 expressing the writer's judgment, than to figure all of the bones 

 as unrelated. Of the jaw parts by which arthrodires are usually 

 identified there are two upper dental plates and the back part 

 of two mandibles. The complete or nearly complete bones 

 are three median occipitals, two upper dental plates, one pos- 

 tero-dorso lateral, two pineals, one tooth of Mylostoma, and 

 several fin rays. 



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