23O NEW YORK STATE MUSEUM 



Eurypterus pachychirus Hall (1859. P Q ^ N. Y. 3:412*, pi. 82) 



Distinguishing characters. Similar to E. r o b u s t u s ; may prove 

 identical. Terminal joints of the sixth pair of legs very broad. 

 Rare in the Waterlime at North Buffalo. 



Eurypterus dekayi Hall (1859. Pal. N. Y. 3:411*, pi. 82) 

 Distinguishing characters. Proportionally short body; short 

 broad carapace; anterior part of the abdomen very broad, posterior 

 part much contracted. Penultimate segment with elongate lateral 

 flanges. 



Occasionally in the Waterlime at North Buffalo. 



Genus dolichopterus Hall 



[Ety. : dofazos, long; izzepov, wing] 



(1859. Pal. N. 7.3:414*) 



Distinguished from Eurypterus by having the sixth pair of 

 cephalothoracic legs long and narrow, with the last two joints of 

 subequal size. Metastoma elongate heart-shaped, as in Ptery- 

 g o t u s . 



Dolichopterus macrochirus Hall (1859. Pal. N. Y. 3:414*, pi. 83, 



83A) 



Distinguishing characters. Robust, elongated body, long, straight- 

 sided carapace, very anterior eyes; strong ?nd thick jointed anterior 

 appendages; extremely long sixth pair of legs. 



Found in the Waterlime beds of North Buffalo. 



Genus eusarcus Grote & Pitt 



[Ety.: eu, well; aap%, flesh (well-fleshed)] 



(1875. Buffalo soc. nat. sci. Bui. 3:1) 



Eurypterids with the anterior six abdominal segments greatly 

 expanded, and the succeeding ones abruptly contracted. The ter- 

 minal joint of the sixth pair of legs is not expanded. 



Eusarcus grandis Grote & Pitt (Buffalo soc. nat. sci. Bui. 3:17) 

 Distinguishing characters. Large size, attaining a length of 2 or 3 

 feet. Subcylindric posterior abdominal segments. 

 In the Waterlime at North Buffalo. 



