XO. 12 



SMITHSONIAN EXPLORATIONS. I917 



Fig. 4. — Mrs. Walcott splitting out Middle Cambrian fossils from 

 slabs of shale blasted out of the fossil-bearing bed of the Burgess Pass 

 quarry. Photograph by Walcott. 1917. 



J''K- 5- ' A--> •''" <i"iiv;iH- rrctpiiiL; in 'i> .iniin.ni { i\',-(iiiiil>ttii [^i>lyf<'di(i. 

 new genus and species Walcott) with iHuncr.)u> tulic fiet and ti-iitaclcs. 

 This and the forms represented by ligs. (> and K belong to undescrilied 

 genera and species and are here illustrated for the t'irst time. 



