NO. lO CAMBRIAN FOSSILS, 4TM CONTRIBUTION RESSER 3 



IPHIDELLA Walcott, 1905 



Iphidella fieldensis, n. sp. 



Microniitra (Iphidella) pamiula Walcott (part), Canadian Alpine Journ., 

 vol. I, no. 2, pi. I, fig. I, 1908; U. S. Geol. Surv. Mon. 51, p. 361, pi. 14, 

 fig. ir, 1912. 



This species was confused with I. panniila but there is Httle re- 

 semblance. /. fieldensis is characterized by a fairly well developed 

 diamond pattern on the older part of the shell, which is more and 

 more obscured toward the margins by increase in prominence of 

 the wavy growth lines. 



Middle Cambrian, Stephen; (loc. 14s) Mount Stephen; (loc. 35k) 

 Burgess Pass, near Field, British Columbia. 



Holotypc. — Walker Mus., Toronto. 



Iphidella pulchra, n. sp. 



Microniitra (Iphidella) paiuiiila Walcott, Research in China, vol. 3, Carnegie 

 Inst. Publ. 54, pi. I, fig. 13, 1913; Smithsonian Misc. Coll., vol. 67, no. 9, 

 p. 482, pi. 106, fig. 17, 1924. 



This is a very beautiful brachiopod. Well-preserved specimens 

 show "spines" extending far beyond the margins of the shells. /. pul- 

 chra carries the diamond pattern to its extreme development. Very 

 large specimens show the pattern interrupted somewhat in the outer 

 part of the shell by rather heavy growth lines. 



Middle Cambrian, Burgess; (loc. 35k) Burgess Pass; (loc. 14s) 

 Mount Stephen, near Field, British Columbia. 



Holotype. — U.S.N.]M. no. 59801. 



OBOLIDAE King 

 LINGULELLA Salter, 1866 



The family Obolidae includes many brachiopod genera, chief of 

 which in Cambrian strata are Ohohis and LingulcUa. Each contains 

 many species, and to both genera are assigned a number of sub- 

 genera. Discrimination of oboloid brachiopods is an inexact pro- 

 cedure at present because no one has yet determined what the charac- 

 teristics essential for classification may be. Relative size and shape, 

 and sometimes shell ornamentation, are the only usable criteria. 



Proper generic names are not available for many Cambrian species. 

 It is evident that most, if not all, of the subgenera in Obolus and 

 LingulcUa are valid genera, but these two names themselves are in 

 question. One thing is certain, namely, that Obolus must be confined 

 to post-Cambrian species. LingulcUa is founded on L. davisi McCoy, 



