JLRT. 4 CAMBRIAN CONCHOSTRACA — ULRICH AND BASSLER 29 



BRADORIA MINOR (Matthew) 



Plate 1, Figure 22 



Leperditiai?) minor Matthew, Trans. New York Acad. Sci., vol. 14, 1895, 

 p. 138, pi. 8, figs. 4a, 4&. 



A single specimen represents this species. It is partly exfoliated, 

 and the preservation of the posterior edge is not wholly satisfactory, 

 but enough is retained to prove the systematic position of the species 

 to be within the genus Bradoria. It agrees with B. scrutator in surface 

 pitting and in the position and degree of development of the ocular 

 tubercle, but differs in the outline of the valves, these being shorter 

 and relatively broader anteriorly. Further, the contour of the valve 

 (a left valve) differs in being less uniformly convex, the surface of the 

 valve being obscurely conical and sloping in every direction from a 

 subcentral apex. In its general aspect, B. minor resembles also 

 B. rugulosa and B. ohesa, and it it thought to be nearer the last than 

 to any other known. 



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

 ford Brook, New Brunswick. 



BRADORIA? STEADI (Matthew) 



Plate 1, Figure 23 



Leperditia steadi Matthew, Trans. Royal Soc. Canada, vol. 7, sect. 4, 1890, 

 p. 160, pi. 7, figs. 13a-13c; Trans. New York Acad. Sci., vol. 14, 1895, p. 137, 

 pi. 8, figs. 7a-7c. 



No specimens of this species are present in the collection, but 

 judging from the figures and description only it differs from Bradoria 

 minor in little save size, being at least twice the width of that form. 

 While it may be seriously questioned whether this is a valid specific 

 difference, it is impossible to determine the point without specimens. 

 Besides, Leperditia steadi may prove to be something very different, 

 though that it should belong to Leperditia seems extremely improba- 

 ble. In the meantime it is thought safer to remove it to Bradoria. 



Occurrence. — Lower Cambrian (Hanfordian, division C16): Han- 

 ford Brook, New Brunswick. 



BRADORIA "PRIMAEVA" (Matthew) 



Plate 1, Figure 29 



Beyrichia (?) primaeva Matthew, Trans. Royal Soc. Canada, ser. 2, vol. 4, 

 sect. 4, 1898, p. 133, pi. 1, figs. 2a-2c. 



The specimen marked as the type of this species is an imperfect 

 mold of the exfoliated exterior of a left valve. It is evidently a species 

 of Bradoria, but with the material in hand it would not be safe to 

 suggest aUiances. As it is impossible to identify the species, the name 

 should be dropped. 



Occurrence. — Lower Cambrian (Hanfordian, division C162): Han- 

 ford Brook, New Brunswick. 



