DEVONIC FISHES OF THE NEW YORK FORMATIONS 1 37 



between this and other species, the following table of measurements is 

 given : 



Length of head shield along median line . . . . 8.3 cm 



Maximum width of head shield - - - - - - 8.3 



Length of dorsomedian - - - - - - - - 5.2 



Maximum width of dorsomedian - - - - - - 4.4 



Maximum width of antero-dorsolateral ■■ - - - - 4.0 



Length of postero-dorsolateral - - 3-8 



Total length of mandible - - 4.6 



Formation and locality. The unique specimen answering to the above 

 description was obtained by Mr F. K. Mixer from the black Rhinestreet 

 shale (Portage) at Sturgeon Point, on the south shore of Lake Erie, near 

 Buffalo, N. Y. It is now preserved in the collection of the Buffalo Society 

 of Natural Sciences, and the writer is indebted to Mr Mixer for the 

 privilege of its description. 



Dinichthys tuberculatus Newberry 



1888 Dinichthys tuberculatus /. S. Neivberry. N. Y. Acad. Sci. Trans. 

 7: 179 



1889 Dinichthys tuberculatus /. S. Newberry. U. S. Geol. Sur. Monogr. 

 16: 98, pi. 32, fig. 3 



1893 Dinichthys tuberculatus E. \V. Claypole. Am. Geol. 12:277 



1897 Dinichthys tuberculatus C, R. Eastman. Mus. Comp. Zool. Bui. 

 31:38 



1899 Dinichthys tuberculatus C. R. Eastman. N. Y. State Geol. 17th An. 

 Rep't, p. 318 



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 indi- 

 cate 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 differ- 

 ence in geological horizon to prevent assigning to this species certain heavy 

 and coarsely tuberculated Dinichthyid plates found in the Middle and 

 Upper Devonic of Wisconsin and Iowa; neither is it possible, except for 

 difference in geological age, to recognize a distinction between the plates 



