NO. 5 MIDDLE CAMBRIAN ANNELIDS I29 



minute hooks arranged in five or six concentric rings (figs, i, 2, 4, 

 and 5). At the posterior end there is a concentric row of stronger 

 hooks as shown by figs, i and 3. 



The proboscis is strong, retractile, and papillose. In fig. 4 it is 

 extended nearly to its full length ; in figs, i and 5 partially con- 

 tracted, and in fig. 2 apparently broken ofi:. 



There are no traces of parapodia or openings on the surface ex- 

 cept at the ends of the body. 



Enteric canal small and extending the entire length of the body 

 from the mouth to the posterior end (fig. 2). The mouth is at the 

 base of the proboscis in front of the bands of hooks (fig. 2). The 

 anus appears to have been at the posterior end, as indicated by the 

 termination of the enteric canal in figs, i and 2. 



The average length of adult specimens is from 8 to 10 cm. One 

 9 cm. in length is 2 cm. across its widest part as it is flattened in the 

 shale. Other specimens are more contracted, shorter, and pro- 

 portionally broader (fig. i). 



Observations. — There is a large series of this species in various 

 conditions of preservation. Some show the annular lines and bands 

 with great distinctness (figs, i and 3) and others are apparently 

 smooth (fig. 2). The proboscis may be protruded (fig. 4), partially 

 pushed out (fig. 5), or absent (fig. 2). Bands of longitudinal 

 muscles are suggested by the lines near the inner curve of fig. i, and 

 concentric muscles by the annular bands. 



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

 member of the Stephen formation, west slope of ridge between 

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

 Burgess Pass, above Field on the Canadian Pacific Railway, British 

 Columbia, Canada. 



OTTOIA MINOR, new species 



Plate 22, figs. 5 and 6 



This species dififers from Ottoia prolifica in its proportionally 

 more slender form when elongated (fig. 5), and straighter outline 

 both when elongated and contracted (fig. 6). The hooks are also 

 much finer and extend farther back on the anterior end. The annular 

 lines and interspaces are also finer and more irregular. 



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

 member of the Stephen formation, west slope of ridge between 

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

 Burgess Pass, above Field on the Canadian Pacific Railway, British 

 Columbia, Canada. 



