122 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ 



discussion of the subject by Dr. G. F. Matthew/ who conckides that 

 Hyolithes and aUied forms should be classed with the annelids, along 

 with Hyolithellus and other slender tubes. 



During the field season of 191 1 we hope to add something more to 

 the information about the animal of Selkirkia. 



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

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

 between Mount Field and Wapta Peak, one mile (1.6 km.) north- 

 east of Burgess Pass, above Field; and (14s) about 2300 feet 

 (701 m.) above the Lower Cambrian and 2700 feet (823 m.) below 

 the Upper Cambrian, in the Ogygopsis zone of the Stephen forma- 

 tion, at the great " fossil bed " on the northwest slope of Mount 

 Stephen, above Field on the Canadian Pacific Railway ; both in 

 British Columbia, Canada. 



SELKIRKIA FRAGILIS, new species 



Plate 19, fig. 8 



A thin tube that when flattened has a diameter at the larger end 

 of from 2.5 to 3 times its length ; the slender proximal end is curved. 

 The largest specimen has a length of 25 mm. This species differs 

 from Selkirkia gracilis (fig. 9), and 5". major (fig. 6) in its greater 

 proportional diameter at the aperture. 



Formation and locality. — Middle Cambrian: (14s) about 2300 

 feet (701 m.) above the Lower Cambrian and 2700 feet (823 m.) 

 below the Upper Cambrian, in the Ogygopsis zone of the Stephen 

 formation, at the great " fossil bed " on the northwest slope of 

 Mount Stephen, above Field on the Canadian Pacific Railway, 

 British Columbia, Canada. 



SELKIRKIA GRACILIS, new species 

 Plate 19, fig. 9 



A number of fine specimens of this species have been found in the 

 same layers of shale with 5". major, but unfortunately none of 

 them show any traces of the animal. The tube is very thin and, 

 unlike S. major, retains the slender, more or less curved proximal 

 end. A comparison of fig. 9 with figs. 6 and 8 shows how this 

 flattened tube differs in form from 5. major and 6^. fragilis. 



The largest tube has a length of 47 mm. and a width of 10 mm. 

 at the aperture. 



^ Trans. Roy. Soc, Canada, 2d ser., Vol. 5, sec. 4, 1899, p. 103. 



