1284 NEW YORK STATE MUSEUM 



PL.ATE 23 



Eurypterus pittsfordensis sp. nov. 



Page 1098 



1 An endognathite referred doubtfully to this species 



2 Seventh and eighth joints of swimming foot showing the 

 formation of the slightly expanded blade, the subtriangular inner 

 appendage of the seventh, the incised margin of the eighth joint 

 (palette) and the minute claw inserted on the same. x2y 2 



3 Cross section of postabdomen, showing the triangular scales 

 on the tergite. Natural size 



4 Section through postabdomen of a very large individual. 

 Natural size 



