THE EURYPTERIDA OF NEW YORK
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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
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.
