. FOSSILS OF THE CAMBRIAN. 



the eyelobes; marked near the posterior margin by the extension of the 

 occipital groove. Facial suture extends outward, with a slight curvature 

 in front of the eyelobe, and then recurves, rounding the lateral extension 

 of the frontal limb; behind the eye it extends backward and outward at an 

 -angle of about 45 for a short distance, and then continues at an angle of 

 25 to the posterior margin of the head. 



Dimensions. Length of head, 6 mra ; breadth of frontal lobe, 2J>5 mm ; 

 length of glabella, including occipital ring, nearly 3.75 mm . 



This distinct form appears to belong to that division of the Concepha- 

 lidae represented by Roemer's genus Pterocephalus, judging by its wide 

 frontal limb and the course of the facial sutures. 



Formation and locality. Upper beds of the Cambrian. On the east side 

 of the canon east of the Hamburg Ridge, Eureka District, Nevada. 



Ptychoparia (Pterocephalus) laticeps H. & W. 



Concephalites (Pterocephalus} laticeps Hall & Whitfield, 1877. 

 Par., vol. iv, p. 221, pi. ii, figs. 4-7. 



Geol. Expl. Fortieth 



This species is given by its authors as occurring in the lowest lime- 

 stones on the west side of Pogonip Mountain, White Pine District, Nevada, 

 In the Eureka District it is found in the upper beds of the Secret Canon 

 shale, opposite the dump of the Richmond mine shaft, Ruby Hill, northeast 

 side of the canon, and in the Hamburg belt of shale east of the Hamburg 

 mine, Eureka District, Nevada. 



Genus ANOMOCARE Angelin. 



Anomocare ? parvum, n. ep. 

 Plate ix, fig. 17. 



Glabella and fixed cheeks united, subquadrangular in form, moderately 

 convex. Glabella tapering gradually from the base to the front, where it 

 is rounded truncate; the surface is depressed convex and marked by four 

 pairs of glabellar furrows, which are short, slightly impressed, and divide 

 the glabella into three subequal lobes, with a somewhat longer anterior 



