No. 448.] DENTITION OF RH VNL lU nj i S. 



Rhynchodus pertenuis, sp. nnv. 



Dental plate narrow and elongate, with sharp and extended 

 cutting edge and knife-blade cross-section; anterior beak prom- 

 inent, no symphysial process, external surface smooth. 



The unique dental plate upon which this species is tounded 

 was obtained from the Chemung of Franklin, in Delaware 

 County, New York, and is preserved in the State Museum at 

 Albany, where the attention of the writer was called to it 1)\ 

 Dr. J. M. Clarke, State Palaeontologist, but not in time to 

 include its description with other fish remains already made 

 known from the same locality.^ The general outline and i)ro 

 portions of this form differ from those of all other spec ies, and 

 the absence of a symphysial process is a very unusual teature. 

 But for the trenchant cutting edge and narrow cross-section, the 



specimen might be readily mistaken for a lower 

 Ptyctodus, instead of Rhynchodus. That it is p 

 dibular element, and referable to the latter genus. ^ 

 of no question. The hollow along the base indie; 



tes the 



a-hich the plate 



; buried in the sup] 



The total length is 9 1 



Kept. State Geol. I 



