DEVONIC FISHES OF THE NEW YORK FORMATIONS 87 



open for a considerable extent posteriorly. The longitudinal mesial line 

 of the anterior face, except near the unworn apex, defined only by the 

 superficial ornament, which consists of par- 

 allel, oblique, transverse, ridges, diverging in 

 pairs from this line and inclined towards the 

 inserted extremity ; posterior face with a nar- 

 row unornamented area, sometimes bounded 

 by a series of denticles on one side ; unworn 

 apex also destitute of ornament. 



Gyracanthus sherwoodi Newberry 



Plate 3, figure 7 



1889 G y r a c a n t li u s s h e r w o o d i y. ^. ^V(7i'- 

 berry. U. S. Geol. Sur. Monogr. i6: 119, pi. 18, fig. | 



Fin spines attaining a length of about 

 15 cm, laterally much compressed, gentl) 

 arched and gradually tapering toward the 

 apex ; internal cavity open as a narrow groow 

 for a considerable distance posteriorly ; sides 

 ornamented with numerous fine, parallel 

 curved ridges, either irregularly pectinated or 

 faintly nodose. 



The only examples hitherto known of 

 this species are those described by Newberry 

 from a single boulder thought by him to have 

 been derived from the Catskill of Tioga 

 county, Pennsylvania. A few fragmentary 

 spines displaying the same ornamentation and 

 agreeing in form with Newberry's originals 



have been obtained from the Chemung group .^ 



near Warren, in the same state, one or two Fig.iy Gyracanthidcs murray i a. s. 



Woodward. Restored drawing of fossil, much 



beingf preserved in the Museum of Compara- reduced, head and abdominal region seen from 



^ ^ _ ^ below, tail twisted to exhibit side view (After 



tive Zoology at Cambridge, Mass. Several smith woodward) 



specimens from the Chemung of southern New York are also preserved in 



the State Museum at Albany. One particularly fine impression, shown in 



