10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 7G 



TUZOIA NODOSA, new species 



Plate 5, figure 4 



A second species based on one small complete valve must be estab- 

 lished from the Lower Cambrian Cranbrook material. 



It is readily distinguished from other species by the large and 

 numerous spines along the dorsal line and by its great width which 

 exceeds any other species. It has four posterior marginal spines like 

 T. polleni, but the remainder of the margin seems to be smoother. It 

 also has short blunt spines on the keel. 



Horizon and locality. — Lower Cambrian, Eager formation; (loc. 

 67g) , near Cranbrook, British Columbia, 



Holotype.—Qiii. No. 80486, U.S.N.M. 



TUZOIA SPINOSA, new species 



Plate 6, figure 4 



Another species ai)])ears to be represented by two fragmentary 

 valves in the red weathered shales of the Eager formation from Cran- 

 i)rook. At first, owing to the large spines on the keel, it was thought 

 that the specimens belonged to T . undosa^ but a more careful com- 

 parison indicates that the differences first observed in the marginal 

 spines actually exist and are not merely a matter of preservation. 

 These spines are arranged in two sets, one a widel}^ and irregularly 

 spaced large set between Avhicli a smaller more even set occurs. 



HoHzon and locality. — Lower Cambrian, Eager formation; (loc. 

 67g), near Cranbrook, British Columbia. 



Holoiype.— Cat. No. 80489, U.S.N.M. 



TUZOIA PRAEMORSA, new species 

 Plate 6, figure 3 ; Plate 7, figure 2 



Two fine Burgess shale specimens Avere first regarded as represent- 

 ing a new genus before the manner of folding under compression and 

 the fact that the keel is sometimes spinose were determined. The 

 plate descriptions indicate the manner of folding in both specimens. 



This species can not be confused with any other in the Burgess 

 shale because of its scalloped frill on the keel and the marginal spines. 

 It is much more like 7\ getzi from the Lower Cambrian. 



Horizon and locality. — Middle Cambrian, Burgess shale; (loc. 35k) 

 near Field, British Columbia. 



Holoiype and paratype.-—C'dX. No. 80488, U.S.N.M. 



TUZOIA GETZI, new species 



Plate 7, figure 3 



Several specimens have been secured from the Lower Cambrian in 

 southeastern Pennsylvania and two of them represent another species 



