TRILOBITA—OPISTHOPARIA. 



285 



Upper Cambric (St. Croix) of Wisconsin; also Nevada. 

 75. D. pepinensis Owen. (Figs. 1587, c; isSS,c,d.) Cambric. 



Fig. 1587. a, Dikellocephalus viinnesotensis, cephalon, without free cheeks, of an 

 average specimen; b^ (upper left) a small variety; c, (upper right) D. pepinensis^ 

 central portion of head. All X Yz- (After Hall.) 



Facial sutures almost parallel to glabella in front of eyes. Py- 

 gidium semielliptical. 



Upper Cambric (Potsdam) of Minnesota, etc. 



Fig. 1588. a, Dikellocephalus minnesoiensis, large pygidium at bottom, with a small 

 one {b) above in center ; r, ci, D. pepinensis, pygidium and free cheek, left and right. 

 All X K- (After Hall.) 



'](i. D. newtonensis Weller. Cambric. 



Very similar to D. pepinensis but palpebral lobes at about the 



