42 PALEONTOLOGY OF THE EUREKA DISTRICT. 
width more than one-half the length of the limb between it and the glabella, 
somewhat flattened and with a narrow groove between it and the depressed 
limb; posterior lateral limbs narrow, marked by the extension of the occip- 
ital furrow within their posterior margin. The facial sutures cut the 
frontal rim obliquely, and recurving inward pass to the palpebral lobes; 
curving around these opposite the central portion of the glabella, they then 
extend obliquely outward and backward, cutting the posterior margin 
beyond a line with the eyelobes. 
Surface smooth to the unaided eye; minutely punctate under a strong 
magnifying power. 
This species is distinguished by its broad fixed cheeks and long frontal 
margin with the flattened rim. 
Formation and locality—Cambrian. Prospect Mountain Group, upper 
beds of the Secret Canon shale, on the opposite side of the cafion from the 
dump of the shaft of the Richmond mine, Ruby Hill, Eureka District, 
Nevada. 
Dicellocephalus ? angustifrons, n. sp. 
Plate x, figs. 1, lab. 
Glabella subquadrate; width at the base equal to the length, but nearly 
one-third greater than the width of the anterior margin; surface moderately 
convex, curving down in front and marked by two pairs of lightly impressed 
glabellar furrows that extend obliquely inward one-third the distance across 
the glabella, the posterior pair nearly separating the posterior triangular 
lobes; occipital ring rather broad and distinctly defined by a strong occip- 
ital furrow; dorsal furrows narrow but strongly impressed; fixed cheeks 
very narrow and hardly separable from the palpebral lobes, which are large, 
elongate, and situated opposite the central portion of the glabella; frontal 
limb merely a line between the glabella and the rounded rim; lateral limbs 
only partly known; they appear to be narrow and rather short. 
Associated with the glabella and fixed cheeks are numerous free cheeks ~ 
that undoubtedly belong to this species. They are triangular with the 
upper angle truncated to form the base of the eyelobe; the outer margin 
is strong, somewhat flattened, and separated from the rapidly ascending 
slope to the furrow at the base of the eye by a sharp narrow groove. The 
