2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



Middle Cambrian, Eldorado; (loc. 58) east side New York and 

 Secret Canyons, Eureka District, Nevada. 

 Cotypcs. — U.S.N.M. no. 24551a, b. 



Micromitra burgessensis, n. sp. 



Micromitra (Iphidella) pannula Walcott, Smithsonian Misc. Coll.. vol. 67, 

 no. 9, p. 481, pi. 106, fig. 16, 1924. 



This species conforms in every respect to the characteristics of 

 Micromitra even though only one valve has been found. The growth 

 lines are pronounced and are wavy and close together. Ribbing is 

 well developed, and the ribs have the usual irregularities. Because 

 of the crinkly growth lines and particularly because of the preserva- 

 tion of long slender spines which extend far beyond the margin, this 

 shell was regarded as the same as /. pidchra. However, a glance at 

 the illustrations shows that the two forms are quite dilTerent and 

 that piilchra is a true Iphidella. 



Middle Cambrian, Burgess; (loc. 35k) Burgess Pass, near Field, 

 British Columbia. 



Holotypc. — U.S.N.M. no. 69646. 



PATERINA Beecher, 1891 



Paterina troyensis, n. sp. 



SccncUa rctiisa Walcott (part), U. S. Geol. Surv. Bull. 30, p. 126, pi. 12, 

 fig. 3a, 1886 (not fig. 3 = Sfcnothccoidcs). 



The specimen doubtfully referred to Sccnella retitsa by Walcott 

 is a brachiopod belonging to Paterina. It is a small form only 1.5 mm 

 long and i mm high. About halfway back a depression follows the 

 position of an ordinary growth line, but this is regarded as an acci- 

 dental feature. The shell appears to be nearly smooth, but this may 

 be due to imperfect preservation. 



Lower Cambrian, Schodack; (loc. 27) Troy, New York. 



Holotypc— U.S.N.M. no. 15369. 



Paterina zenobia (Walcott) 



Micromitra (Paterina) stissiiiyoisisF Walcott (part), U. S. Geol. Surv. 



Mon. 51, p. 353, pl- 3, fig- le, 1912. 

 Micromitra (Paterina) stissingensis ora Walcott, idem, p. 354, 1912. 

 Micromitra zenobia Walcott, idem, p. 342, text fig. 23, 1912; Smithsonian 



Misc. Coll., vol. 67, no. 9, p. 481, pi. 106, figs. 1-7, 1924. 



Middle Cambrian, Burgess; (loc. 35k) Burgess Pass, (Iocs. 61 j, 

 35k') West slope Mount Field; (loc. 14s) Mount Stephen near 

 Field, British Columbia. 



Holotypc. — U.S.N.M. no. 5831 1; plesiotypes, nos. 56907, 51483, 

 69631-7. 



