NO. 13 DIKELOCEPHALUS AND OTHER GENERA 381 



Fonnatio)! and locality. — Upper Cambrian (62) in thin layer of 

 limestone in Dimderberg shale, in canyon immediately north of 

 Adams Hill, Eureka District, Nevada' (C. D. Walcott, 1880). 



SAUKIA PEPINENSIS (Owen) 



Plate 67, figs. 1-13, 13a 



Dikelocephalns pepincnsis Owen, 1852, Reptt Geol. Surv. Wis., Iowa, and 



Minn., p. 574, pi. i, figs. 9, ga-h. (Describes and illustrates species.) 

 Dikelocephalns pepincnsis Owen, Hall, 1862, Rept. Geol. Surv. Wis., Vol. i, 



p. 22, text figs. 3, 4. (Illustrates cranidium and pygidium.) 

 Dikelocephalns pepincnsis Owen, Hall, 1863, Sixteenth Ann. Rept. State 



Cab. Nat. Hist., p. 142, pi. 9, figs. 1-4; pi. 10, figs. 14-17. (Describes in 



detail and illustrates species. Fig. 13 does not appear to belong with 



this species.) 

 Dicelloccphalns pepincnsis Owen, Winchell, 1864, American Journ. Sci., 



2d ser., Vol. 37, p. 229. (Comments on cranidium and describes an 



associated pygidium.) 

 Dikcloccphalus pepincnsis Owen, H.\ll, 1867, Trans. Albany Inst., Vol. 5, 



p. 122, pi. 4, figs. 1-4 ; pi. 5, figs. 14-17. (Republishes text and illustrations 



of 1863.) 

 Dicelloccphalns pepincnsis Owen, Chamberlin, 1883, Geol. Wisconsin, 



Vol. I, p. 130, figs. i6c-f, after Hall, 1863. (Copies figures of Hall with- 

 out description.) 

 Dicelloccphalns pepincnsis Owen, Walcott, 1886, Bull. U. S. Geol. Survey, 



No. 30, p. 35, paragraph 66. (Notes occurrence of species in Highland 



Range, Nevada.) 

 Dikcloccphalus pepincnsis Owen, Brogger, 1897, Nyt Mag. for Naturvid., 



Vol. 36, p. 17s, fig. 9. (Illustrates pygidium after Hall.) 



This species is readily recognized by its strong, flattened frontal 

 rim and convex compact pygidium with a narrow, slightly flattened 

 border. The description, given by Hall in 1863, is so detailed and 

 accurate that it does not appear necessary to attempt to add to it. 



Fragments of the species occur in great abundance in the shaly 

 sandstones of the upper horizon of the St. Lawrence sandstones of 

 Wisconsin. 



Comparisons with other species referred to Saiikia are given under 

 observations on the genus. 



Specimens of a cranidium and a pygidium that appear to be identi- 

 cal with those from Wisconsin occur in the Highland Range of 

 Nevada in a limestone in association with fragments of a large trilo- 

 bite that indicates a species which may be Dikelocephalns minnc- 

 sotensis.^ 



^ In Monograph 8 of the U. S. Geological Survey, p. 45, the locality of the 

 type specimen is incorrectly given as just south of the Hamburg Mine. The 

 geological horizon is correct but not the exact locality. 



^ Bull. U. S. Geol. Survey, No. 30, 1886, p. 35, paragraph 66. 



