442 BULLETIN 53, UNITED STATES NATIONAL MUSEUM. 



13896. Nyassa parva Walcott. Cotypes. 



Middle and Upper Devonian. Eureka District, Nevada. 



Walcott, Mon. VIII, U. S. Geol. Surv., 1884, p. 173, pi. 15, figs. 

 14, 14a. 



24554. Obolella ? ambigua Walcott. Cotypes. 



Lower Pogonip (Cambrian). Ridge east of Hamburg 

 Mine, Eureka District, Nevada. 

 Walcott, Mon. VIII, U. S. Geol. Surv., 1884, p. 67, pi. i, figs. 



2a-2C. 



= Elkania ambigua. 



18322. Obolella atlantica Walcott. Cotype. 



Lower Cambrian. Conception Bay, Newfoundland. 



Walcott, Proc. U. S. Nat. Mus., XII, 1889, p. 36; Tenth Ann. 

 Rept. U. S. Geol. Surv., 1890, p. 611, pi. 71, figs, i-ic. 



14891. Obolella chromatica Billings. Plesiotype. 



Lower Cambrian. L'Anse au Loup, Labrador. 



Walcott, Bull. No. 30, U. S. Geol. Surv., 1886, p. 112, pi. 11, figs, 

 i-ib; Tenth Ann. Rept. U. S. Geol. Surv., 1890, p. 611, pi. 



71, figS. 2-2D. 



14892. Obolella circe Billings. Plesiotype. 



Lower Cambrian. Trois Pistoles, Quebec, Canada. 



Walcott, Bull. No. 30, U. S. Geol. Surv., 1886, p. 118, pi. 10, figs. 3, 

 3a; Tenth Ann. Rept. U. S. Geol. Surv., 1890, p. 611, pi. 71, 

 figs. 3, 3a. 



15347. Obolella crassa (Hall). Plesiotype, 



Lower Cambrian. Troy, New York. 



Walcott, Bull. No. 30, U. S. Geol. Surv., 1886, p. 114, pi. 10, figs. 

 ia, ic, ie; Tenth Ann. Rept. U. S. Geol. Surv., 1890, p. 612, 

 pi. 71, figs. 4a, 4c, 4c 



24555. Obolella discoidea Hall and Whitfield. Cotj 7 pes. 



Upper Cambrian. Eureka District, Nevada. 



Hall and Whitfield, Rept. U. S. Geol. Expl. 40th Par., IV, Pt. II, 

 1877, p. 205, pi. 1, figs. 1, 2.— Walcott, Mon. VIII, U. S. 

 Geol. Surv., 1884, p. 14. 



35264. Obolella | Glyptias) favosa Linnarsson. Plesiotypes. 



Lower Cambrian. Yestergotland, Bithingen, Sweden. 

 Walcott, Proc. U. S. Nat. Mus., XXIII, 1901, p. 675. 



14889. Obolella gemma Billings. Plesiotype. 



15349. Lower Cambrian. Tro> T , New York, and Bic Harbor, 



Quebec, Canada. 



Walcott, Bull. No. 30, U. S. Geol. Surv., 1886, p. 116, pi. 10, figs. 

 2, 2b-2e; Tenth Ann. Rept. U. S. Geol. Surv., 1890, p. 612, 

 pi. 71, figs. 5-5C; pi. 72, figs. 2, 2a. 



= Bicia gemma. 



