14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



IDAHOIA Walcott, 1924 



Idahoia explanata (Whitfield) 



Conocephalhcs (Ptychaspis) explanatus Whitfield, Ann. Rep. for 1879, 

 Wisconsin Geol. Surv., p. 49, 1880; Geol. Wisconsin, vol. 4, p. 181, pi. i, 

 figs. 27, 28, 1882. 



Ptychoparia explanafa Miller, N. A. Geol. Pal., p. 565, 1889. 



The specimens in the Museum collections identified by Whitfield 

 are used for this generic reference. 



Upper Cambrian, Franconia; (loc. 79) Hudson, Wisconsin. 

 Holotype. — Univ. Wisconsin; metatypes, U.S.N.M. no. 94372. 



Idahoia wyomingensis, n. sp. 

 Ptychoparia (Lmichocephalus) wlsconsinensis Walcott (part), U. S. Geol. 

 Surv. Mon. 32, p. 461, pi. 64, figs, i, la, 1899 (not ib = /. hanuda; ic = 

 an undetermined species from Wisconsin). 



Walcott's illustrations represent three species, the cranidium and 

 cheek from Soda Butte Creek, constituting the new species. The 

 figure copied from Hall is not I. wisconsinensis as stated, but /. 

 hcmmla, and the pygidium belongs to an undescribed species, possibly 

 a Ptychaspis. 



Compared with /. imsconsinensis, the new species is somewhat 

 shorter and smaller in size. 



Upper Cambrian, Dry Creek; (loc. I5ie) Soda Butte Creek, 

 Yellowstone National Park, Wyoming. 



Cotypes.—U.S.^M. no. 35225. 



IDDINGSIA Walcott, 1924 



Iddingsia affinis (Walcott) 

 Ptychoparia (Euloma?) affinis Walcott, U. S. Geol. Surv. Mon. 8, p. 54, 



pi. 10, fig. 12, 1884; idem, 32, pt. 2, p. 457, pi. 65, fig. 8, 1899. 

 Euloma affinis Walcott, Smithsonian Misc. Coll., vol. 57, no. 13, p. 362, 1914. 



Upper Cambrian, Secret Canyon; (loc. 63) northeast of Adams 

 Hill, Eureka District, Nevada. 

 Holotype. — U.S.N.M. no. 24642. 



INGLEFIELDIA Poulsen, 1927 



Inglefieldia perola (Walcott) 

 Ptychoparia perola Walcott, Smithsonian Misc. Coll., vol. 67, no. 3, p. 91, 

 pi. 12, fig. 7, 1917. 



Although the suture anterior to the eye is less divergent than in 

 species previously assigned to Inglefieldia, yet there is no essential 

 difference, and therefore /. perola adds a western representative to 

 the genus. 



