lO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



EHMANIELLA, n. gen. 



It seems necessary to make a genus for the forms which are about 

 midway between Ehniania and Elrathia. 



Compared to Ehnmnia, Ehmaniella is characterized by the greater 

 width of the cranidium, heavier eye hnes, vertical striae on the wider 

 preglabellar area, and a pygidium with fewer segments. The glabella 

 and fixigenes are apt to be granulose or lined. Comparing the new 

 genus with Elrathia, the differences in the cranidium are only minor, 

 except for greater width, but the pygidium of Ehmaniella is smaller 

 and has the pleural divisions and furrows more clearly developed, 

 extending to the margin with but little loss. 



Genotype. — Crephicephalus (Loganelhts) quadratis Hall and Whit- 

 field. 



Ehmaniella quadrans (Hall and Whitfield) 



Crephicephalus ? (Loganclhis) quadrans Hall and Whitfield, U, S. Geol. 



Expl. 40th Par., vol. 4, p. 238, pi. 2, figs. 11-13, 1877. 

 Ptychoparia quadrans Walcott, U. S. Geol. Stirv. Bull. 30, p. 199, pi. 29, 



figs. 4-4b, 1886. 



Middle Cambrian, Ophir ; north of Brigham, Wasatch Range, and 

 (loc. 3id) Blacksmith Fork Canyon, Bear River Range, Utah. 



Holofypc and paratype. — U.S.N.M. no. 15432. 



ELRATHIA Walcott, 1924 



Elrathia occidentalis (Walcott) 



Ptychoparia occidentalis Walcott, U. S. Geol. Surv. Mon. 8, p. 51, pi. 10, 

 fig. 5, 1884. 



Middle Cambrian, Eldorado; (loc. 55a) east slope Prospect Moun- 

 tain, Eureka District, Nevada. 

 Holotype. — U.S.N.M. no. 24612. 



Elrathia palliseri (Walcott) 

 Ptychoparia palliseri Walcott, Canadian Alpine Journ., vol. i, pt. 2, p. 244, 

 pi. 3, fig. 6, 1908. 



Middle Cambrian, Stephen ; (loc. 14s) IMoiint Stephen, above Field, 

 British Columbia. 



Holotype. — U.S.N.M. no. 94344. 



Elrathia permulta (Walcott) 



Ptychoparia permtdta Walcott (part), Smithsonian Misc. Coll., vol. 67, no. 4, 

 p. 145, pi. 21, fig. I, 1918 (fig. 2=zE. dubia). 



Middle Cambrian, Burgess; (loc. 35k) Burgess, near Field, British 

 Columbia. 



Holotype. — U.S.N.M. no. 65516. 



