DEVONIAN FISHES OF IOWA 273 



Formation and locality. Base of the Waverly series; Boyle 

 county, Kentucky. 



Genus elonichthys Giebel. 



Trunk more or less deeply fusiform. Mandibular suspenso- 

 rium very oblique ; jaws stout and teeth acutely conical, ar- 

 ranged in two series — an inner row of well-spaced laniaries and 

 .an outer row of numerous, closely arranged small teeth; bones 

 of head and opercular apparatus ornamented with tubercula- 

 tions and striae. Fins large, with fulcra, the rays branching 

 distally, covered with ganoine, and the more robust sculptured. 

 Pectoral, pelvic, dorsal and anal fins with short base-line: 

 dorsal opposed to space between pelvic and anal fins: upper 

 caudal lobe much produced, the fin deeply forked and inequi- 

 lobate. Scales of moderate thickness, very slightly imbricating, 

 covered with ganoine, more or less sculptured; ridge-scales im- 

 mediately in advance of median fins much enlarged. 



The American species of this genus are few in number, and 

 confined to the Lower Carboniferous and Coal Measures of New 

 Brunswick and the United States respectively. European spe- 

 cies are numerous and locally very abundant, especially in the 

 Lower Carboniferous of Scotland. The Scottish forms have 

 been exhaustively treated by Dr. Traquair in several important 

 monographs, the most recent of which are included among the 

 publications of the Palaeontographical Society and of the Royal 

 Society of Edinburgh. Of interest in the present connection is 

 a small and elaborately ornamented species, first described in 

 1904 and afterwards more fully illustrated, known as yet by but 

 two nearly perfect individuals, and designated as E. striatulus* 

 Concerning this rare species the author remarks that he has re- 

 ferred it to the genus Elonichthys "on account of its general 

 aspect, and the form and position of the unpaired fins, though 

 the condition of the fin-fulcra deviates considerably from that 

 which is usual in the genus. In all its details it is strikingly dif- 

 ferent from every other known species. ' ' 



* Summary of Progress of the Geol. Survey for 1903 (1904), p. 121. Trans. 



Roy. Soc. Edinb. (1907), 46, pt. 1, p. 107. Ganoid Fishes of the British Car- 

 boniferous Formations, Part 1, no. 3, in Monogr. Palseontogr. Soc. for 1907. 



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