1 62 NEW YORK STATE MUSEUM 



the tubercles, when worn by use, become elongated in the direction of the 

 rows to which they belong, others in an oblique direction. The coarseness 

 of tuberculation, in proportion to the size of the plates, is greater than in 

 any other species yet described. 



Formation and locality. State Quarry beds (Upper Devonic) ; near 

 North Liberty, Johnson co., la. 



Dipterus fleischeri (Newberry) 



plate 7, figure 2 



1897 Ctenodus fleischeri J. S. ATeivberry. N. Y.Acad. Sci. Trans. 16:302, 

 pi. 24, fig. 25 



Upper dental plates thin, slightly concave, triangular in outline ; coronal 

 surface transversed by six rows of rounded obtuse tubercles increasing in 

 size from the posterior angle outwards. At least the anterior or innermost 

 rows of tubercles are continuous almost to the posterointernal angle. 



Besides the type, only one other example of this species has yet been 

 brought to light. This is a large upper dental plate, preserved in counter- 

 part, now the property of the New York State Museum. It is from the 

 Catskill of Delaware county, N. Y., and being more complete than New- 

 berry's original, we present a figure of it herewith. Its relations are 

 evidently with D. u d d e n i and D. m o r d a x, as shown by the small 

 number of coarsely tuberculated costae ; but in size it is much larger, the 

 length of the inner margin being fully 5 cm. 



Formation and locality. Catskill sandstone (Chautauquan) ; Tioga 

 county, Pennsylvania, and Franklin, Delaware co. N. Y. 



Dipterus sherwoodi Newberry 

 1875 Dipterus ^\\<tT:\\ 00 A.\ J. S. Newberry. O. Geol. Sur. Rep't. Palaeont. v. 2, 



pt 2, p. 61, pi. 58, fig. 17 

 1889 Dipterus (Ctenodus) sherwoodi J. S. Newberry. U. S. Geol. Sur. 



Monogr. 16: 118, pi. 27, fig. 32 



Of this species no other examples are known but the type specimen, 

 which is imperfect. In the text of Newberry's monograph, this is deter- 

 mined as "apparently one of the upper palate teeth of a species of Dip- 



