200 IOWA GEOLOGICAL SURVEY 



stone of Ohio. The typical locality for D. tuberculatus is in the 

 Chemung conglomerate of Warren, Pennsylvania, but according 

 to Newberry, the same form occurs also in the Upper Devonian 

 of Belgium. 



Formation and locality. Chemung beds (Chautauquan) ; War- 

 ren, Pennsylvania. Also, according to Newberry, in the Psam- 

 mites de Condroz, near Liege, Belgium. Either this or a very 

 similar species is also represented in the Middle and Upper De- 

 vonian of Ohio, Wisconsin and Iowa. 



Dinichthys curtus Newberry. 



1888. Dinichthys curtus J. S. Newberry, Trans. N. Y. Acad. Sci. 7: 179. 



1889. Dinichthys curtus J. S. Newberry, Monogr. U. S. Geol. Sur. 16: 156, pi. 



48, fig. 3; pi. 53, fig. 1-4. 

 1893. Dinichthys curtus E. W. Claypole, Rep't Ohio Geol. Sur. 7: 606. 

 1893. Dinichthys curtus A. A. Wright, Rep't Ohio Geol. Sur. 7: 623. 

 1900. Dinichthys curtus C. R. Eastman, Jour. Geol. 8: 33. 



1905. Dinichthys curtus L. Hussakof, Bull. Am. Mus. Nat. Hist. 21: 409, pi. 



15, fig. 1; pi. 16. 



1906. Dinichthys curtus L. Hussakof, Mem. Am. Mus. Nat. Hist. 9, p. 112, 



text-fig. 5, pi. 12. 



1907. Dinichthys curtus C. R. Eastman, Mem. N. Y. State Mus. 10, p. 138. 



Newberry's description of this species is as follows: 



"Fishes of moderate or small size; head a nearly equilateral 

 triangle, measuring about a foot on a side; cranium, maxillary 

 and mandible similar in character to those of Dinichthys inter- 

 medins, but only half to two-thirds as large, and the mandible 

 bears two subordinate prominences back of the turned up tooth- 

 like extremity ; also the posterior end of the cutting edge is set 

 with two or three unequal denticles in place of the series of even, 

 lancet-like points in the same position on the mandible of D. 

 intermedins. The anterior ventrolateral plate is scimiter- 

 shaped, eight inches long by two and a half inches wide, being 

 relatively narrower than the corresponding bone in any other 

 species known." 



Occurring typically in the Cleveland shale of Ohio, this species 

 is also reported by Newberry from the Chemung of Pennsyl- 

 vania, although no precise indications as to locality are given. 

 Investigation shows that detached plates of a species fully as 

 large as D. curtus, possibly even larger, occur in the Chemung 



