FOSSILS OF THE CAMBRIAN. 



This is a very striking and pretty species, and is not liable to be mis- 

 taken for any described American form, and it appears to be distinct from 

 any European species known to me, although allied in a slight degree to 

 Agnostus princeps Salter. 



Formation and localities. Cambrian. Prospect Mountain.' limestone, 

 upper portion; Ruby Hill, Richmond mine, 700-foot level; and east slope 

 of the northern portion of Prospect Mountain, Eureka District, Nevada. 



Agnostus seclusus, n. sp. 

 Plate be, fig. 14. 



Cephalic shield strongly convex, a little longer than wide, with a slight 

 contraction posteriorly and margined by a narrow, rim-like border that has 

 a distinct groove between it and the lateral lobes; dorsal furrows well 

 defined, united anteriorly, but not dividing the lateral lobes in front, pos- 

 teriorly each turns obliquely outward, a short distance from the margin, 

 cutting off the inner angle of the lateral lobes Glabella short about one- 

 half the length of the shield, strongly convex and squarely truncated in 

 front; at about the anterior third a broad, short furrow penetrates on each 

 side a short distance, and posteriorly a rounded node is separated from 

 each lateral angle by slight furrows; the lateral lobes slope rapidly to the 

 marginal groove on the sides and more gradually to the front 



Surface finely granulose. 



Dimensions. Length, 3 mm j breadth, nearly the same ; depth of shield, 

 1.25 mm . 



Thoracic segments and caudal shield unknown. 



This species is characterized by the tumid, short, truncated glabella 

 and broad lateral lobes. 



Formation and locality. Cambrian. Prospect Mountain Group; upper 

 portion Secret Canon shale, on the east side of Secret Gallon, Eureka Dis- 

 trict, Nevada. 



