l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



Middle Cambrian, Stephen; (loc. 14s) Mount Stephen, near Field, 

 British Columbia. 



Holatype.— v. S.N. M. no. 96482. 



Helcionella orientalis (Walcott) 



Stcnothcca nujosa orientalis Walcott, Proc. U. S. Nat. Mus., vol. 29, p. 16, 



1905. 

 Helcionella rngosa orientalis Walcott (part), Research in China, vol. 3, 



Carnegie Inst. Publ. 54, p. 91, pi. 5, fig. 15a, 1913 (not fig. 15=^ H. 



shantungensis). 



The species is restricted to the form at the first locality, which ac- 

 cording to Dr. Walcott's practice is the type locality. 



Middle Cambrian, Changhia; (loc. C21) Changhia, Shantung, 

 China. 



Holotypc— U.S.N. M. no. 57776. 



Helcionella shantungensis, n. sp. 



Helcionella rngosa orientalis Walcott (part), Research in China, vol. 3, 

 Carnegie Inst. Publ. 54, p. 91, pi. 5, fig. 15, 1913 (see H. orientalis). 



This species is wider at the base than H. orientalis and the rugosi- 

 ties are not so coarse. The striations are also finer and weaker. 



Middle Cambrian, Changhia; (loc. C18) east of Changhia. Shan- 

 tung, China. 



Holotype. — U.S.N.M. no. 57775. 



Helcionella triangularis (Matthew) 



Stcnothcca triangularis Matthew, Trans. Roy. Soc. Canada, vol. 3, sec. 4, 

 p. 58, pi. 6, figs. 15, 15a, 1886. 



Middle Cambrian, St. John ; Hanford Brook. New Brunswick. 

 Holotype and paratypc. — Walker Mus. (?). 



Helcionella manuelensis (Matthew) 



Plninulites nianuclciisis M.xtthew, Trans. New York Acad. Sci., vol. 15, 

 p. 145, fig. I, 1896. 



Middle Cambrian, Manuels ; Manuels Brook, Conception Bay, 

 Newfoundland. 



Holotype.— Walker Mus. (?). 



SCENELLA Billings, 1872 



Diverse forms are referred to Scenclla, particularly post-Cambrian 

 species. A list of Cambrian species referred to the genus is given 

 with cross references. 



