DESCRIPTION OF PLATE 5 Continued. 



Pelagiella clytia (Walcott) (p. 89). 



14. View of the outer whorl of the type specimen of the species, X 10. U. S. Nat. Mus., Cat. No. 57786. 



From Locality 047, Upper Cambrian, Ch'au-mi-tien limestone at Ch'au-mi-tien, Shan-si. 

 Helcionella rugosa orientalis (Walcott) (p. 91)- 



15 Side view of a rather strongly curved specimen, X 10. From Locality CJ8, Middle Cambrian, 



Ch'ang-hia limestone, east of Ch'ang-hia, Shan-tung. U. S. Nat. Mus., Cat. No. 57775- 

 150. Side view of a slender, banded specimen, X 10. From Locality C 21, Middle Cambrian, Ch'ang- 

 hia formation at Ch'ang-hia, Shan-tung. U. S. Nat. Mus., Cat. No. 57776. 



Hyolithes cybele Walcott [see plate 6, fig. 7] (p. 92). 



16 (X 3) and i6b (X 2). Ventral and dorsal views of typical specimens of the species from Locality 



02, Middle Cambrian, Kiu-lung group, south of Yen-chuang, Shan-tung. U. S. Nat. Mus., 



Cat. Nos. 57787 and 57788. 

 160. Ventral view of a specimen (X 4) from Locality 022, Middle Cambrian, Ch'ang-hia limestone, 



Ch'ang-hia, Shan-tung. U. S. Nat. Mus., Cat. No. 57789. 

 i6c. Exterior and end views of operculum associated with this species in Liau-tung, X 4. From 



Locality 35 n, Middle Cambrian, Fu-ch6u series, Manchuria. U. S. Nat. Mus., Cat. No. 57790. 



Hyolithes daphnis Walcott (p. 93). 



17. Dorsal view of the type specimen, with outline of cross-section. Natural size. From Locality 



C64, Upper Cambrian, Kiu-lung group, 2.7 miles (4.3 km.) southwest of Yen-chuang, Shan- 

 tung. U. S. Nat. Mus., Cat. No. 57797. 



Hyolithes delia Walcott (p. 94). 



18. Dorsal view of the type specimen of the species, X 6. From Locality C 3, Lower Cambrian, Man-t'o 



shales, southwest of Yen-chuang, Shan-tung. U. S. Nat. Mus., Cat. No. 57798- 



Hyolithes sp. undt. Walcott (p. 94). 



19. Fragment of a species of Hyolithes, with a subtriangular aperture, associated with Orthotlieca dor is, 



X 6. From Locality 032, Lower Cambrian, drift bowlder, Southern Shan-si. U. S. Nat. 

 Mus., Cat. No. 57796. 



Hyolithes sp. undt. Walcott (Operculum) (p. 94). 



20. Operculum associated with Hyolithes cybele, X 6. From Locality C 4, Middle Cambrian, Kiu-lung 



group, limestone in shale, southwest of Yen-chuang, .Shan-tung. U. S. Nat. Mus., Cat. No. 

 57795- 

 Orthotheca cyrene Walcott (p. 94) . 



21. Ventral view and transverse section of a typical form of this species, X 4. U. S. Nat. Mus., Cat. 



No. 57799. 



210. Dorsal view of a specimen showing the broad groove on the dorsal face, X 4- U. S. Nat. Mus., 

 Cat. No. 57800. 



Figures 21 and 210 are drawn from specimens found at Locality C47, Upper Cambrian, Ch'au-mi-tien 

 limestone, Ch'au-mi-tien, Shan-tung. 



Orthotheca cyrene dryas Walcott (p. 95). 



22. 22 l , and 22C. Dorsal and side views and outline of section, X 7- U. S. Nat. Mus., Cat. No. 57803. 

 220. Dorsal view, X 5. U. S. Nat. Mus., Cat. No. 57804. 



226. Dorsal view (X 3) of specimen. U. S. Nat. Mus., Cat. No. 57805. 



All of the specimens illustrated are from Locality 02, Middle Cambrian, Kiu-lung group, 2 miles 

 (3.2 km.) south of Yen-chuang, Shan-tung. 



Orthotheca glabra Walcott [see plate 6, fig. 7] (p. 97). 



23. A partly exfoliated specimen (X 8) from Locality 071, Middle Cambrian, Ki-chou formation 



from 4 miles (6.4 km.) south-southwest of Tung-yii, Shan-si. U. S. Nat. Mus., Cat. No. 57566. 

 230. A minute, slender, broken specimen ( X 8) from Locality C 72, Middle Cambrian, Ki-chou forma- 

 tion 4 miles (6.4 km.) east of Fang-lan-chon, Shan-si. U. S. Nat. Mus., Cat. No. 57567. 



Orthotheca daulis Walcott (p. 95). 



24. Ventral view of the type specimen, X 2.5. From Locality 023, Middle Cambrian, Ch'ang-hia 



formation, east-southeast of Ch'ang-hia, Shan-tung. U. S. Nat. Mus., Cat. No. 57809. 

 240. Transverse section of specimen associated with the specimen represented in fig. 24. U. S. Nat. 

 Mus., Cat. No. 57810. 



238 



