88 PALEONTOLOGY OF THE EUBEKA DISTRICT. 



CRUSTACEA. 

 Genus LEPEEDITIA Eonalt 



Leperditia bivia White. 



Leperditia bivia White, 1874. Expl. and Surv. West 100th Merid. Prelim. Notice 

 Invert. Foss., p. 11 j ibid., vol. iv, pt. 1, p. 58, pi. iii, figs. 7o-d, 1875. 



This species is very abundant in the upper beds of the Pogonip Group, 

 at Lone Mountain, 18 miles northwest of Eureka, White Mountain, and the 

 Fish Creek Mountains, Eureka District, Nevada. 



The original type specimens were from the SchelKCreek Range of 

 Nevada. 



Associated with this species we find two smaller species not unlike some 

 varieties of L. Canadensis (Can. Organic Remains, dec. iii, p. 92, pi. xi, figs. 

 6, 7, 9, 10, 1858), the determination and illustration of which is left for fu- 

 ture study. 



Genus BEYEICH1A McCoy. 

 Beyrichia, sp. T 



This is an interesting species, as it is of the type of B. regularis Eni- 

 mons (Amer. Geol., pt. 2, p. 219, 1858), of the Hudson River Group of Ohio. 



Owing to the imperfect condition of the specimens its further identifi- 

 cation is delayed in the hope of obtaining better material. It is associated 

 with Leperditia bivia, at White Mountain, Eureka District, Nevada. 



Genus PLUMULITES Barrande. 



The presence of this rare genus in American strata, west of Ohio, has 

 not hitherto been recorded, and now we have but a single plate to show it. 

 This is triangular in its general form, with the basal margin sigmoidal and 

 the surface ornamented with the characteristic lines parallel to the sigmoidal 

 margin. It occurs in the lower portion of the Pogonip Group, on the 

 southwest end of McCoy's Ridge, Eureka District, Nevada. 



