46 PALEONTOLOGY OF THE EUBEKA DISTEIOT. 



rows; occipital furrow distinctly defined; occipital ring strong, with a small 

 spine on the center of the posterior portion ; dorsal furrows well defined 

 along the sides of the glabella; fixed cheeks of medium width, palpebral 

 lobes unknown ; an ocular (?) ridge crosses the anterior portion of the 

 right fixed cheek, so as to indicate a moderate sized eyelobe between it and 

 the postero-lateral limb; frontal limb as a narrow rim; postero-lateral limbs 

 rather narrow, extended and marked by a strong furrow within the poste- 

 rior margin. 



Surface finely punctate. 



This species and the preceding are closely related, judging from the 

 parts which we have for comparison. It is hoped that in some more favor- 

 able locality entire specimens may be obtained of these and the many other 

 species known only by fragments, so that the generic characters can be 

 determined with greater certainty and more positive specific references 

 made. 



Formation and localities. Cambrian. Prospect Mountain limestone at 

 base of Secret Cafion shale, in New York Cafion, and also in a small expos- 

 ure of Cambrian limestone on the west side of the Mahogany Hills, in 

 Antelope Valley, Eureka District, Nevada. 



Genus PTYCHOPAEIA Corda. 8 



Ftychoparia (?) Prospectenals, n. sp. 

 Plate ix, fig. 20. 



The general outline of the head is moderately convex, semicircular, 

 the width being about twice the length. 



The glabella is sub conical, truncate in front and marked by three pairs 

 of short, slightly impressed glabellar furrows; occipital ring distinctly de- 

 fined by a narrow, lightly impressed occipital furrow; fixed cheeks broad, 

 of equal elevation with the glabella, and extending beyond it anteriorly, 

 the space between them on the broad frontal limb being taken by a small 



6 The reason for using the generic term Ptychoparia rather than Crepicephalus, as used by 

 Messrs. Hall and Whitfield in the Paleontology of the Fortieth Parallel Exploring Expedition, is given 

 in a bulletin of the Geological Survey now ready for the press, entitled a "Review of the Fauna of the 

 St. John Formation." The relations of the genera Conocoryphe, Ptychoparia, Crepicephalus, Soleno- 

 pleura, Liostracus, and Conocephalites are mentioned. C. D. W. 



