FOSSILS OF THE CAMBRIAN. 



41 



transverse furrow that unites them; occipital ring of medium width and 

 separated from the glabella by a well-defined, but not deeply impressed 

 occipital furrow; dorsal furrows of medium strength on the sides of the 

 glabella but scarcely shown in front; fixed cheeks unusually narrow and 

 rising directly up to the large, elongate palpebral lobes; anteriorly they 

 slope into the groove of the frontal limb; posterior extension and postero- 

 lateral limbs unknown; frontal limb between the glabella and furrow nearly 

 obsolete, extending beyond the furrow as a broad subspatulate, somewhat 

 convex margin. The facial suture curves a little outward in front of the 

 eye as far as the furrow of the frontal limb and then recurves inward around 

 to the front; after curving around the large eyelobe to near the posterior 

 margin, its further course has not been traced. 



Surface smooth or slightly punctate. 



Thorax and pygidium unknown. 



Formation and localities. Cambrian. , Prospect Mountain Group, central 

 portion Secret Canon shale in New York Canon, and upper layers of same 

 on north side of the canon opposite the dump of the shaft of the Richmond 

 mine, Ruby Hill, Eureka District, Nevada. 



Dicellocephalus Richmondensis, n. sp. 

 Plate x, fig. 7. 



Glabella and fixed cheeks, united, quadrangular in form, the width 

 being a little greater than the length. Glabella elongate-subquadrangular, 

 lateral margins slightly converging anteriorly, and with the front a little 

 rounded; length and breadth as three to four; surface moderately convex, 

 and marked by a slightly impressed posterior pair of furrows, directed 

 obliquely inward two-thirds the distance to the median line, and two pairs 

 anterior to these that are just discernible upon the smooth surface; occip- 

 ital ring of medium width, distinct; occipital furrow distinct, but not deeply 

 impressed; dorsal furrows well defined at the sides but only a line in front 

 of the glabella; fixed cheeks broad, rising slightly from the dorsal furrows 

 to the palpebral lobes and sloping away before and behind quite rapidly; 

 frontal limb rather long and wide, the marginal rim broadly arcuate, the 



