240 rALJ^.ONTOLOGY. 



lobes convex, marked by three or four divided ribs, exclusive of the anterior 

 single one. 



Surface of the head and cheeks marked by fine anastomosing lines, 

 radiating from the eye and front of the glabella. 



Formation and locality. — In dark gi'eenish, thinly-laminated shales of 

 the Quebec group, in canon above Call's Fort, Wahsatch Range, Utah. Col- 

 lected by S. F. Emmons, esq. 



Genus DIKELLOCEPHALUS Owen. 



DlKELLOCEPHALUS QUADEICEPS U. Sp. 

 Plate I, figs. 37-40. 



Glabella and fixed cheeks united, quadrangular in form, with a regu- 

 larly and symmetrically arcuate front margin. Glabella elongate quad- 

 rangular, a little expanded and rounded in front, three-fourths as wide across 

 the middle as the length above the occipital furrow, very gibbous or some- 

 what inflated; marked by three pairs of transverse furrows, which extend 

 about three-fourths of the distance to the center, not in the least oblique, and 

 so faint as to be detected only on the closest examination, or by the reflec- 

 tion of light along the surface; occipital furrow very distinct; ring strong 

 and robust, supporting a strong, thickened spine of undetermined length on 

 the posterior margin. The base of the spine is broad, and the spine directed 

 backward and upward. 



Fixed cheeks of moderate size, strongly convex, a little more than one- 

 third as wide at the eye as the width of the glabella, and rapidly declining 

 to the antero-lateral angles. Eye-lobes small, situated rather behind the 

 middle of the length of the head; ocular ridges distinct, strongly directed 

 forward in their passage from the eye to the glabella. Frontal limb very 

 short, not extending beyond the frontal margin of the glabella, and strongly 

 curving backward to the point of intersection with the facial sutures. 



Facial sutures commencing at the anterior margin on a line with the 

 inner angle of the eye-lobe, and running directly back to the eye in a 

 straight line; behind the eye, the direction is outward, but its exact course 

 has not been ascertained. Lateral limb not observed. 



A pygidium associated with the glabella is paraboloid in form, and 



