FOSSILS OF THE NIAGAEA GROUP. 157 



of the head, and in the absence of the broad, somewhat projecting and 

 flattened anterior border of that species, and the surface features of the 

 crust are also of much finer texture. From L. nereus, Hall (16th Rept- 

 State Cab., p. 226), to which it is closely related, it differs in the propor- 

 tionally shorter cephalic shield, in the more curved lateral lobes, and in 

 the absence of the anterior prolongation of the border. 



Formation and locality : In limestones of the Niagara group, at Yellow Springs, Ohio. 



