130 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



OTTOIA TENUIS, new species 



This species is based on a small slender annelid that has a slender 

 proboscis ; its anterior end has a band of hooks and the posterior 

 end a long whip-like appendage that is longer than the body. The 

 body, exclusive of the caudal appendage, is from 25 to 30 mm. in 

 length in the four specimens collected. One 30 mm. long has a 

 width of 2 to 2.5 mm. as it flattened in the shale. 



Ottoia tenuis differs from 0. prolifica and 0. minor in its slender 

 body and long posterior appendage. 



Formation and locality. — Middle Cambrian: (35k) Burgess shale 

 member of the Stephen formation, on the west slope of the ridge be- 

 tween Mount Field and Wapta Peak, one mile (1.6 km.) northeast 

 of Burgess Pass, above Field, British Columbia. 



BANFFIA, new genus 



The description of the type species includes all that is known of 

 the genus. 



Genotype. — BanfUa constricta, new species. 



Stratigraphic range. — The stratigraphic range is through about 

 no feet of shale or from the lower Phyllopod bed,^ where it occurs 

 in a hard siliceous shale, up through to nearly the summit of the 

 Burgess shale where the shale is coarser-grained, steel gray in color 

 on fresh surface, and weathering to a dirty buff color. 



Geographic distribution. — On the slope of the ridge between 

 Wapta Peak and Mount Field, north of Burgess Pass, and about 

 3800 feet above Field on the line of the Canadian Pacific Railway, 

 British Columbia, Canada. 



Observations. — The reference of this genus to the Gephyrea is 

 tentative. With its elongate body and annular lines it resembles 

 Ottoia, and in the absence of interior structure the evidence is too 

 incomplete to refer it elsewhere. 



Generic name derived from Banff, name of town on Canadian 

 Pacific Railway, Alberta, Canada. 



BANFFIA CONSTRICTA, new species 



Plate 21, figs. 5 and 6 

 Body elongate, constricted midway. The anterior and larger 

 section is elongate-spatulate in outline and the posterior section a 

 narrow ellipse truncated at the ends. The constriction between the 



^ Phyllopod bed is the name now given to a stratum of shale about 5 feet 

 in thickness in the Burgess shale in which many Phyllopod crustaceans occur. 



