DEVONIAN FISHES OF IOWA 199 



The measurements of this element evidently indicate an imma- 

 ture individual, since considerably larger plates of the same kind 

 have been found elsewhere in New York State and also in the 

 Genesee Black Shale of Louisville, Kentucky. Some of the plates 

 from the latter locality exceed the average proportions of D. 

 pustulosus, are as a rule thicker, and differ also in the details of 

 ornamentation. Skeletal parts belonging doubtfully to this 

 species have also been described from the Naples shale at Stur- 

 geon Point, near Buffalo, New York. 



Formation and locality. Typically from the Genesee shale 

 (Senecan) in the vicinity of Bristol Center and Canandaigua 

 Lake, New York. Detached plates agreeing in proportions and 

 ornamentation also known from the corresponding formation 

 near Louisville, Kentucky. Doubtfully represented also in the 

 Naples shale (Portage beds) of western New York. 



Dinichthys tuberculatus Newberry. 



1888. Dinichthys tuberculatus J. S. Newberry, Trans. N. Y. Acad. Sci. 7, 



p. 179. 



1889. Dinichthys tuberculatus J. S. Newberry, Monogr. U. S. Geol. Surv. 16, 



p. 98, pi. 32, fig. 3. 

 1893. Dinichthys tuberculatus E. W. Claypole, Amer. Geol. 12, p. 277. 

 1897. Dinichthys tuberculatus C. E. Eastman, Bull. Mus. Comp. Zool. 31, 



p. 38. ' 

 1899. Dinichthys tuberculatus C. R. Eastman, 17tb Ann. Rept. N. Y. State 



Geol. p. 318. 

 1907. Dinichthys, tuberculatus C. R. Eastman, Mem. N. Y. State Mus. 10, 



p. 137. 



An imperfectly definable species, known only by detached 

 plates which are remarkable for their relatively great thickness, 

 and coarsely tuberculate style of ornamentation. The known 

 portions of the abdominal armor indicate a species rather less 

 than one-half the size of D. intermedins. In the present state 

 of our knowledge, there are no reasons other than difference 

 in geological horizon to prevent assigning to this species certain 

 heavy and coarsely tuberculated Dinichthyid plates found in 

 the Middle and Upper Devonian of Wisconsin and Iowa ; neither 

 is it possible, except for difference in geological age, to recognize 

 a distinction between the plates known under this name and the 

 so-called D. precursor Newberry, from the Corniferous lime- 



