THE EURYPTERIDA OF NEW YORK 281 
ference, for the segments of the fourth pair are throughout shorter 
than those of the fifth, but as noted above, the single type is poorly 
preserved, was therefore apt to mislead and is not conclusive in this 
regard. In view of the fact that Drepanopterus, which clearly leads 
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(Sewer ; . 3) 
Figure 63 Stylonurus logani H. Woodward. Original figure. (From Woodward) 
phylogenetically to Stylonurus, exhibits a much greater difference between 
these two leg pairs, it is a fair deduction that such difference also existed 
in typical Stylonurus, though less pronounced and perhaps in various 
- gradations. 
