56 PALEONTOLOGY OF THE EUREKA DISTRICT. 
and at various horizons between the two in New York, Secret, and Sierra 
Cafions, and on the Hamburg Ridge. In the Black Hills it occurs at 
about the horizon of the upper portion of the Prospect Mountain Group of 
the Eureka District, Nevada. 
In a report on the Cambrian fauna of the United States, now in course 
of preparation, the types of the various species given in the synonymy of 
Ptychoparia Oweni will be illustrated. 
Ptychoparia Anytus H. & W. 
Plate ix, fig. 26. 
Orepicephalus (Loganellus) anytus Hall & Whitfield, 1877. Geol. Expl. Fortieth Par., 
vol. iv, p. 219, pl. ii, figs. 19-21. 
Compare Crepicephalus=Ptychoparia planus Whitfield, 1877. Geology and Resources 
of the Black Hills of Dakota, p. 341, pl. ii, figs. 21-24. Also Crepicephalus 
(L.) = Ptychoparia Montanensis Whitfield, 1876. Rep. Recon. Carroll, 
Montana, to Yellowstone Nat. Park, Ludlow, p. 141, pl. i, figs. 1, 2. 
The specimen illustrated by fig. 26 of plate ix, differs from the type of 
P. Anytus in having a somewhat narrower, more quadrilateral glabella, 
and also a thicker anterior rim to the head, but on comparing several spe- 
cimens with the typical specimens from Schell Creek, Nevada, these varia- 
tions are seen in each series, and no satisfactory differences remain upon 
which to base a distinct species. The figure given by Messrs. Hall and 
Whitfield shows a larger, broader, and more conical glabella in proportion 
to the head than that of fig. 26, plate ix, of this report, the two figures in 
the two reports giving the range of variation in the head as far as known. 
On comparing the type of P. planus Whitfield, with a head of P. Anytus, 
broken just as the type of P. planus is, there does not appear to be the 
slightest difference between the two. We labor, however, under the dis- 
advantage of comparing with a cast of a fragment of the head as the origi- 
nal type, and cannot decide positively until more and better material is 
collected from the original locality. 
P. Montanensis is a closely allied species of which we have not seen 
the original type. 
Formation and locality—Cambrian. In the upper beds of the Secret 
Canon shale, on the east side of New York and Secret Cafions, Eureka 
District, Nevada. i 
