FOSSILS OF THE CAMBRIAN. 13° 
e 
The species is well represented, and appears to be characteristic of the 
upper portion of the Cambrian and the lower horizon of the Silurian, 
Pogonip Group. It occurs in the Secret Canon shale of the Cambrian on the 
eastern side of the cafon directly east of Ruby Hill; in the limestone of 
the Pogonip Group northeast of Adams Hill; on the ridge southeast of the 
Jackson mine; on the southwest spur of Wood Cone, and southeast of the 
Hamburg mine, Eureka District, Nevada. 
Lingulepis ? minuta H. & W. 
Lingulepis ? minuta Hall & Whitfield, 1877. Geol. Expl., Fortieth Parallel, vol. iv, 
p. 206, pl. i, figs. 3, 4. 
This species has nearly the same vertical range and geographical 
distribution as Lingulepis Mera, usually occurring in the same localities. 
The type specimens were obtained in the Eureka District by the members 
of the Fortieth Parallel Geological Survey. 
Genus LINGULA Bruguiére. 
Lingula ? manticula White. 
Plates ix, fig 3, and xi, fig. 2. 
Lingula? manticula White, 1874. Expl. and Sury. West 100th Merid.; Prelim. 
Rep. Pal., p. 9. Lbid., vol. iv, pt. 1, p. 52, pl. iii, figs. 2a, b, 1875. 
The range of variation among the specimens we have referred to this 
species is greater than exists between them and our conception of L. ? 
manticula, as obtained from the description and illustrations given by 
Dr. White, and without a direct comparison with the type specimens to 
determine any specific differences, if they exist, we consider them as one 
species. As none of the examples show the internal characters of the shell, 
the doubtful character of the generic reference remains unchanged. 
The type specimens were collected in the Schell Creek Range of Ne- 
yada, at an horizon in the Silurian, equivalent probably, to the horizon at 
which the species occurs in the Pogonip Group. F 
