DEVONIC FISHES OF THE NEW YORK FORMATIONS I47 



Genus glyptaspis Newberry 

 A provisional genus including Arthrodires of large or even gigantic 

 size, known only by plates of the abdominal armor. Ornamentation con- 

 sisting of fine stellate tubercles, closely arranged and often becoming con- 

 fluent in irregular or vermiculating ridges. Overlapping margins of plates 

 broad, beveled to a thin edge, and sometimes striated. 



Glyptaspis verrucosa Newberry 



1889 Glyptaspis verrucosus J. S. Newberry. U. S. Geol. Sur. Monogr. 

 16: 158, pi. 13, fig. I, 2 



Under this name several large plates with strongly beveled edges, and 

 with central portion displaying peculiar ornamentation, have been described 

 by Newberry from the Cleveland shale of Ohio. One of the two plates 

 figured by this author is identifiable as the anterior, the other as the pos- 

 terior ventromedian, both represented in inverted position. The larger of 

 these, as compared with the corresponding element amongst other forms, 

 indicates a creature fully equaling Titanichthys in size. Of the head shield, 

 and other portions of the armor aside from the ventromedian plates, nothing 

 is at present known, nor has the species been recognized with certainty 

 beyond the confines of the Cleveland shale of Ohio. 



Glyptaspis abbreviata sp. nov. 



Plate i; 



A few fragmentary plates are preserved in different collections from 

 the Black slate of Kentucky (Genesee) and Portage shale of western New 

 York, which display the vermiculating type of ornamentation peculiar to 

 Glyptaspis, but until recently there has been insufficient material for fram- 

 ing a satisfactory diagnosis of the species represented. The relatively 

 smaller size of the plates, their fineness of ornamentation, and difference in 

 geological horizon lead one to suspect that another than the type species 

 was present during the earlier part of the Upper Devonic, and this inference 

 would seem to be borne out by a recent fortunate discovery, which we owe 

 to Dr J. M. Clarke. 



