44 PALEONTOLOGY OF THE EUREKA DISTRICT. 
Occipital ring narrow, flattened; occipital furrow very shallow; fixed 
cheeks narrow, separated from the glabella by distinctly marked dorsal 
furrows, and sloping rapidly from the palpebral lobes before and behind; 
palpebral lobes elongate, slightly sinuate, and with a groove within the 
margin; frontal limb broad, rather short, sloping down to a line or groove 
beyond which the flattened margin extends, the width of the margin nearly 
equaling the distance between it and the glabella; postero-lateral limits of 
medium width, with the extension of the occipital furrow marking their 
posterior portion; their lateral extension is a little greater than one-half the 
length of the head. 
Facial suture directed outward from in front of the eyelobe to the 
anterior rim of the head, around which it abruptly curves, terminating at 
the front margin; behind the eye it passes obliquely backward at an angle 
of 25° with the posterior margin of the head, cutting the latter at a distance 
from the dorsal furrow equal to the width of the anterior emd of the glabella. 
Surface finely granulose under a strong magnifying glass. 
Thorax and pygidium unknown. One associated pygidium is much 
like that illustrated by Hall and Whitfield, Geol. Expl. Fortieth Par., vol. 
iv, pl. i, fig. 39. 
Formation and locality—Cambrian. Upper portion of Prospect Mount- 
ain Group, near the Bullwhacker mine, Eureka District, Nevada. 
Dicellocephalus Marica, n. sp. 
Plate x, fig. 13. 
Glabella and fixed cheeks subquadrate in outline, narrowing somewhat 
towards the front. Glabella subquadrangular and almost squarely truncate 
in front, which is not quite as wide as the base; strongly convex, anil 
marked by three pairs of furrows, the two anterior pair but slightly im- 
pressed and very short; the. posterior pair extend obliquely inward one- 
third the distance across from each side, and are united by a slight trans- 
verse furrow; occipital ring strong and elevated; occipital furrow well 
defined; dorsal furrows strongly impressed; fixed cheeks moderately convex, 
narrow in front, widening at the palpebral lobes, and sloping away rapidly 
in front, and less so back of the eyelobes; eyelobes narrow, semicircular, 
