24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 93 



Upper Cambrian, Secret Canyon; (loc. 60) near Richmond Mine, 

 Eureka District, Nevada. 



Holotype and paratypcs. — U.S.N.M. no. 24617. 



Dunderbergia simulator (Hall and Whitfield) 



Crepiccphalus (Logaiicllus) simulator Hall and Whitfield, U. S. Geol. Expl. 



40th Parallel, vol. 4, p. 218, pi. 2, figs. 16-18, 1877. 

 Inonyia simulator Walcott, Smithsonian Misc. Coll., vol. 64, 1916. 



Upper Cambrian, Secret Canyon ; Eureka District, Nevada. 

 Lcctotypc. — U.S.N.M. no. 24575; paratypes, no. 24573. 



Dunderbergia granulosa (Hall and Whitfield) 



Crepiccphalus (Loganellus) granulosa Hall and Whitfield, U. S. Geol. Expl. 



40th Parallel, vol. 4, p. 214; pi. 2, figs. 2, 3, 1877. 

 Ptychoparia granulosa Walcott, U. S. Geol. Surv. Monogr. 8, p. 57, 1884. 

 Inouyia granulosa Walcott, Smithsonian Misc. Coll., vol. 64, no. 3, p. 204, 1916. 



Upper Cambrian, Secret Canyon; (loc. 61) near Hamburg Mine 

 and other locaHties, Eureka District, Nevada. 

 Holotype.— U.S. 'NM. no. 24573. 



Dunderbergia pustulosa (Hall and Whitfield) 



Ptychaspis pustulosa Hall and Whitfield, U. .S. Geol. Expl. 40th Parallel, vol. 4, 

 p. 223, pi. 2, fig. 27, 1877. 



Upper Cambrian, Secret Canyon ; Pogonip Mountain, White Pine 

 District, Nevada. 



Holotype. — U.S.N.M. no. 24579. 



Dunderbergia suada (Walcott) 



Ptychoparia suada Walcott, Proc. U. S. Nat. Mus., vol. 13, p. 274, pi. 21, fig. 9, 

 1890. 



Upper Cambrian, Wilberns ; (loc. 70) Baldy Mountain, near Mor- 

 gans Creek, 8 miles northwest of Burnet, Texas. 

 Holotype.-— \].S.^.M. no. 23860. 



EHMANIA, n. gen. 



Many Middle Cambrian species characterized by a peculiar pygidium 

 have been referred to variovis genera during the past 55 years. 

 When they arc gathered together and their features noted, a definite, 

 clear-cut genus emerges. To this is assigned the name of Philip 

 Ehman, of Logan, Montana, who has been of material assistance in 

 restudying the classic region along the north side of the Gallatin 

 Valley. 



Diagnosis. — Cranidium of a very common type. Glabella tapered, 

 rounded in form, distinctly demarcated by dorsal furrow ; glabellar 



