28 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 78 



BRADORIA CONCINNA (Matthew) 



Plate 3, Figure 9 



Schmidtellai?) pervetus mut. concinna Matthew, Canadian Record Sci., vol. 8, 

 1902, p. 464; Geol. Surv. Canada, Rept. Cambrian Rocks, Cape Breton, 1903, 

 p. 173. 



The "mutation" concinna was founded on a single specimen. It 

 was in a good state of preservation, but required cleaning to bring out 

 all of its characters. As now developed, the ocular tubercle is shown 

 to be very slightly developed, and this feature serves very well in 

 distinguishing the species from the otherwise closely similar Bra- 

 doria spectator spinosa. The ocular tubercle is not perfectly preserved 

 nor is the antero-cardinal angle complete in the type, but both are 

 satisfactorily shown in a specimen belonging to the Walcott collections. 

 Comparing the species as known by these two specimens with Bradoria 

 spinosa, B. concinna is smaller, slightly longer transversely, its dorsal 

 angles less produced, the dorsal slope a trifle fuller, and the surface 

 ornament perhaps a shade coarser than in B. spinosa. 



The type of Schmidtella? pervetus being too poorly preserved to be- 

 determinable, it is suggested to raise the supposed variety concinna to 

 the rank of a species and to drop the name pervetus. 



Occurrence. — Lower Cambrian (Lower Etcheminian, division Elc, 

 ElcJ): Boundary Brook, Escasonie, Nova Scotia. (Walcott locality 

 IZt.") Dugald Brook, Nova Scotia. 



Cat. No. 50510 U.S.N.M. (Ut"). 



BRADORIA CAMBRICA (Matthew) 



Plate 1, Figure 10; Plate 3, Figures 14, 15 



Schmidtella cambrica Matthew, Trans. New York Acad. Sci., vol. 14, 1895, 

 p. 137, pi. 7, figs. 10a, 106. 



In its outline the type of this species, is much like Bradoria spectator 

 and even more like B. obesa. It is smaller, however, and its ocular 

 node less developed. From the former it difi'ers considerably in hav- 

 ing the central part of the valves much more elevated. B. obesa 

 approaches it in this respect, but B. cambrica is a trifle shorter and 

 has coarser surface punctation. B. concinna is longer transversely. 



Matthew's type of S. cambrica, when figured and described by him, 

 did not exhibit an ocular tubercle, but it shows clearly enough now 

 since the obscuring matrix has been removed. 



Occurrence. — Lower Cambrian (Hanfordian, division C163): Han- 

 ford Brook, St. Martins, New Brunswick. (Walcott localitj^ 2^.) 



Plesiotype. —C&t. No. 50533, U.S.N.M. (2i). 



