Barbour — Carboniferous Eurypterids of Nebraska. 509 



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. 



Eurypterus (Anthraconectes) nebraskensis, sp. nov. 



The main features of Eurypterus nebraskensis are the vermi- 

 form appearance, the long spatulate paddles, and the spinous 

 ridges upon the last five tergites of the postabdomen. 



Fig. 1. 



Fig. 2. 



Fig. 1. Eurypterus nebraskensis. x 3/2. 



Fig. 2. Eurypterus, sp., ventral view, showing a very large metastoma 

 and opercular process, x 3/2. 



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 ante- 

 riorly. At the genal angles, the scale-markings are smaller 

 and closely crowded together. The preabdomen is widest at 



