12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



China 



Hclc'wncUa ? chirius (Walcott) (Poorly preserved) 



" rtigosa chincnsis (Walcott)^//. ch.incnsis 



7-T I • jt • , 7- /,Tr 1 N (H. oriciifalis 



Helcionella rtigosa oncntalis (Walcott) 



H. shautungcnsis 

 " f simplex Walcott 

 " acuticosta pacifica Saito ^ H. pacifica 



Helcionella rugosa (Hall) 



Mctopioma ? rugosa Hall, Pal. New York, vol. i, p. 306, pi. 83, fig. 6, 1847. 



Stenotheca rugosa Walcott (part), U. S. Geol. Surv. Bull. 30, p. 128, pi. 12, 

 figs. lb, c, 1886 [not fig. I = H. curticei; la =: H. fordi; id, e = Stenothc- 

 coides troyensis] ; idem, loth Ann. Rep., p. 617, pi. 74, figs, ib, c, i8gi 

 [not fig. i^H. curticei; la = //. fordi; id^=H. sp.; ie=:H. zvalcotti; 

 if, g = H. halli; ih, i ^=z Stenothecoides troyeusis]. 



Helcionella rugosa Grabau and Shimer (part), N. A. Index Foss., vol. 1, 

 p. 607, fig. 8iob, 1909. 



Great confusion w^as introduced into tliis species by illustration 

 of the New York forms in 1886 and 1891. After that other workers 

 assuined these animals to be highly variable and referred many 

 diverse fonns to II. rugosa. 



Available specimens were segregated according to kind and locality. 

 Thereupon, several species appeared as clearly defined units and are 

 here defined. H. rugosa occurs only in the Hudson valley ; at all 

 other localities throughout the world the name was misapplied. 



After careful comparison the name rugosa was restricted to the 

 form which agrees with Hall's original description and illustration. 

 Possibly if the original type could be studied this choice might have 

 to be altered. 



Lower Cambrian, Schodack; (loc. 2y) Troy, and other localities, 

 New York. 



Hololype. — A.M.N.H. no. 212; plesiotypes, U.S.N.M. no. 15365. 



Helcionella halli, n. sp. 



Stenotheca rugosa Walcott (part), loth Ann. Rep. U. S. Geol. Surv., p. 617, 

 pi. 74, fig. ig, 1891 [see //. rugosa]. 



This species has a more circular outline than any other from New 

 York. It is also high and has its apex overturned parallel to the base 

 of the shell. 



Lower Cambrian, Schodack; (loc. 35) i^ miles north of Bald 

 Mountain, northwest of Greenwich, New York. 



Holotype.—V.S.^.^i. no. 96472. 



