Page:AmJourSci 4 38 228 507-510.djvu/3

 Eurypterus probably swam well, but it is not unlikely that it chose to frequent sandy and muddy bottoms.

Undoubtedly the Nebraska eurypterids are closely related to Anthraconectes of the Illinois Coal Measures, described some years ago by Meek and Worthen.

The main features of Eurypterus nebraskensis are the vermiform appearance, the long spatulate paddles, and the spinous ridges upon the last five tergites of the postabdomen.

In Eurypterus nebraskensis the preabdomen is but slightly inflated, and grades insensibly into the postabdomen, giving a vermiform appearance. The telson is long and slender. The scale markings are distinct, and very regular in pattern over the tergites. They are semilunar, and the effect is that of imbricated scales of fishes. The scale-markings continue upon the base of the cephalothorax, but in decreasing numbers anteriorly. At the genal angles, the scale-markings are smaller and closely crowded together. The preabdomen is widest at