152 T. E. Savage — New Species of Arthropods. 



ginal border. It is divided into 14 segments by narrow trans- 

 verse furrows which are deeper at the sides than over the 

 median portion. The surface of the pleural lobes is gently 

 convex, with a somewhat flattened border. They are divided 

 into about 11 segments which end a short distance from the 

 lateral margins, and become obsolescent posteriorly. 



This species closely resembles Dalmanites tridentiferus, 

 which was described by Shumard from strata of about the same 

 age on the Missouri side of the river. It is especially dis- 

 tinguished from Shumard's species by having the anterior 

 median extension short and concave, w T ith margin entire, instead 

 of having that extension prolonged into a three-lobed process. 



