32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



Bridge figured one of tlie two species present at the locality. The 

 holotype is a well-preserved cranidium. 



This species is characterized by its relative narrowness immedi- 

 ately in front of the eyes. The eyes are not parallel to the dorsal fur- 

 row, but make a wide angle with the axis. Eyelines are rather heavy. 

 The cranidium is arched considerably laterally, this being accentuated 

 by the pronounced downward depression of the anterior angles of 

 the brim. Longitudinally the head is also highly arched, the greatest 

 curvature being in the anterior half. The preglabellar area is bulged 

 a bit and the thickened rim is sharply upturned. 



Upper Cambrian, Uavis ; (loc. iik) near shaft of Federal Lead 

 Mine No. 4, Flat River, Missouri. 



Holotype. — U.S.N.M. no. 93011. 



Elvinia dakotensis, n. sp. 



Elvinia rocmcri Bridge (part), U. S. Geol. Surv. Prof. Pap. 186-M, p. 251, 

 pi. 69, figs. 14, 16, 1937. 



This species is nearest like E. missouriensis, dififering in the round- 

 ing of the anterior portion of the glabella and the slightly narrower 

 width immediately in front of the eyes. E. dakotensis also has less 

 rugged relief in the various portions of the brim. In E. dakotensis 

 the glabella does not rise so much as the fixigenes, and the longi- 

 tudinal curvature, which is considerable, forms a rather even curve. 



The libragenes are large and wide, with a strongly curved outer 

 margin, particularly toward the genal angle. The genal spine is short 

 and small. The associated pygidium has an axis which stands well 

 above the flat pleural lobes. 



Upper Cambrian, Deadwood ; (loc. 88a) northern part of Dead- 

 wood, Black Hills, South Dakota. 



Cotypes. — U.S.N.M. no. 93024. 



Elvinia utahensis, n. sp. 



Elvinia rocmcri Bridge (part), U. S. Geol. Surv. Prof. Pap. 186-M, p. 251, 

 pi. 69, fig. 22, 1937. 



This species is characterized by rugged relief due to the depth of 

 all furrows, the arching of the preglabellar area and of the fixigenes 

 and the depression of the anterior angles of the brim. The eyes are 

 large and situated rather far forward. 



Upper Cambrian, Orr; (loc. 32t) Fandango Spring Canyon, east 

 side Dugway Range, Utah. 



Holotype. — U.S.N.M., no. 93026. 



