81 



spines, wider forehead lobe of the p;labella, wider and less convex 

 thoracic axis and shorter and thicker spines to the pygidium 

 which curve toward each other instead of spreading. This 

 species has been, generally, confounded with C. pleurexantbemus, 

 but a comparison of numerous fragments as well as entire spec- 

 imens has shown the above mentioned variations to be constant. 

 It was first pointed out as a distinct species, from an examina- 

 tion of the specimen illustrated, about twenty years ago, by 

 Dr. C. A. Miller, now deceased, in whose memory we now dedi- 

 cate the species. 



Found in the Hudson River Group, at Cincinnati, and now in 

 the collection of Wm. F. E. Gurley. 



-11 G. 



