FOSSILS OF THE CAMBRIAN. 5T 
Ptychoparia granulosus H. & W. 
Grepicephalus (Loganellus) granulosus Hall & Whitfield, 1877. Geol. Expl. Fortieth 
Par., vol. iv, p. 214, pl. ii, figs. 2, 3. 
Types from the Eureka District. The species occurs at the summit of 
the Secret Cafion shale, across the cation from the dump of the Richmond 
shaft, Ruby Hill, and in the lower part of the Pogonip Group, southeast 
of the Jackson mine, Eureka District, Nevada. 
Ptychoparia Haguei H. & W. 
Orepicephalus (Loganellus) Haguei Hall & Whitfield, 1877. Geol. Expl. Fortieth Par., 
vol. iv, p. 210, pl. ii, figs. 14, 15. 
Types from Pogonip Mountain, White Pine District, Nevada. 
In the Eureka District this species has a range nearly equal to that of 
P. Gallatinensis, but, as yet known, it does not extend down below the sum- 
mit of the Secret Cafion shale. At that horizon it occurs on the eastern 
side of Secret Cation and the opposite side of the cation from the dump of 
the Richmond shaft, Ruby Hill, and at the summit of the Hamburg shale 
east of the Hamburg mine, and also in the lower part of the Pogonip 
Group at the same locality. 
Ptychoparia nitidus H. & W. 
Orepicephalus (Loganellus) nitidus Hall & Whitfield, 1877. Geol. Expl. Fortieth Par., 
vol. iv, p. 212, pl. ii, figs. 8-10. 
Crepicephalus (Loganellus) simulator Hall & Whitfield, 1877. Geol. Expl. Fortieth 
Par., vol. iv, p. 218, pl. ii, figs. 16-18. 
When studying a large series of specimens of Ptychoparia nitidus it was 
observed that the head and pygidium varied in size, and that there were no 
differences between the larger sized specimens of the head and the type of 
Crepicephalus (L) simulator. 
The types of the two species described by Messrs. Hall and Whitfield 
were collected in the Eureka District by the geologists of the Fortieth Par- 
allel Exploring Expedition, and the species is quite abundant in strata near 
the summit of the Cambrian series. 
. 
