ABT. 4 CAMBRIAN CONCHOSTRACA — ULRICH AND BASSLER 27 



BRADORIA OBESA (Matthew) 



Plate 1, Figure 27; Plate 3, Figure 13 



Bradoria vigilans Matthew (part), Bull. Nat. Hist. Soc. ,New Brunswick, No. 18, 

 1899, p. 205; Canadian Record Sci., vol. 8, 1902, p. 454; Geol. Surv. Canada, 

 Rept. Cambrian Rocks, Cape Breton, 1903, p. 164. 



Bradoria vigilans mut. ohesa Matthew, Canadian Rec. Sci., vol. 8, 1902, p. 455. 



A single specimen only is marked as representing this supposed 

 mutation of Bradoria vigilans. As stated above in the remarks on that 

 species, we find that three of the specimens labeled B. vigilans are 

 really in every respect like the type of the mutation ohesa. Further, 

 we find these four specimens so constant in their characters and so 

 readily distinguished by their shorter and more obese form, and even 

 finer surface punctae, from the figured typical specimens of B. vigilans 

 that we can not hesitate to regard them as specifically distinct. The 

 outline of the valves of B. ohesa is considerably like that of B. per- 

 spicator and B. spectator, differing only in being a trifle more obtuse in 

 the ventral and anterior parts, but the ocular tubercle is so much 

 better defined and the carapace so much thicker that there should be 

 little difficulty in distinguishing them. In the last feature the species 

 is allied to B. camhrica, in which, however, the ocular tubercle is much 

 less developed. 



Occurrence. — Lower Cambrian (Etcheminian, division El6-Elc?, 

 E26, E36?): Dugald Brook, Cape Breton, Nova Scotia. Walcott 

 locality 13n'', 10;?''.) 



Cat. Nos. 50528, 50529, U.S.N.M. 



"SCHMIDTELLA? PERVETUS" Matthew 



Plate 1, Figure 26 



Schmidtella (?) pervetus Matthew, Bull. Nat. Hist. Soc, New Brunswick, No. 18, 

 1899, p. 206, pi. 4, figs. 3a-c; Canadian Rec. Sci., vol. 8, 1902, p. 464, pi. 2, 

 figs, llo-c; Geol. Surv. Canada, Rep. Cambrian Rocks, Cape Breton, 1903, 

 p. 172, pi. 13, figs, lla-c. 



As noted under the discussion of Bradoria concinna, the type of 

 Schmidtella (?) pervetus Matthew was so poorly preserved as to be 

 indeterminable, but the type of S. pervetus mutation concinna proved 

 to be a vaHd species of Bradoria. Under the circumstances it seems 

 best to recognize Bradoria concinna and to drop the name Schmidtellaf 

 pervetus. 



Occurrence. — Lower Cambrian (Upper Etcheminian, division E3c) : 

 Dugald Brook, Cape Breton, Nova Scotia. 



