EURYPTERUS. PPP. 35 



part of the body is across the fourth segment, which is 

 more than three times the width of the last one. 



Telson very long, having a length equal to nearly one- 

 half tlie length of the entire animal. 



The palpi and swimming feet are comparatively longer 

 than in the preceding species. 



Test marked by minute imbricating scales. On the pos- 

 terior tergal position of the carapace and somites the 

 scales are larger than on the other jiortions of the surface. 



A somewhat distorted specimen has a length of 99 mm., of 

 which 49 mm. pertain to the telson ; the width of the fourth 

 somite is 22 mm. and of the last one 7 mm. 



This species is distinguished from E. Mansjieldi by its 

 shorter carapace, com[)aratively wider body, longer and 

 stronger telson and the eyes are more oblique and distant. 



Formation and locality. — Found in the shale immedi- 

 ately below the Darlington cannel coal, near Cannelton, 

 Darlington township, Beaver county, Pennsylvania. Hor- 

 izon, Alleghany river series. 



