NO. 5 • MIDDLE CAMBRIAN ANNELIDS 11/ 



Stratigraphic range. — The stratigraphic range is limited to a band 

 of dark siliceous shale about 4 feet in thickness forming a part of 

 the Burgess shale member of the Stephen formation. 



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. 



Generic name derived from Ayshea, the name of a mountain peak 

 north of Wapta glacier, British Columbia, Canada. 



AYSHEAIA PEDUNCULATA, new species 



Plate 23, figs. 8 and 9 



Body elongate, slender. Segments numerous and clearly defined 

 by lines on which many minute shallow pits occur, several of the 

 lines having 13 pits on the exposed side of the body. Head small; 

 a central narrow longitudinal section has a rounded lobe on each 

 side of its posterior half that suggests large eyes ; the anterior end 

 appears to have two short, slender tentacles projecting forward. 

 Parapodia large and attached in such a manner as to have two lines 

 of pits and three segments between each pair of parapodia, and one 

 line of pits and two segments between the lines of pits w^hich merge 

 into the anterior and posterior outline of each parapodia or foot. 

 Hook-like and straight, jointed setse are attached to the parapodia. 

 Traces of a small enteric canal occur in the posterior half of the body. 



Dimensions. — Length of specimen preserving 10 parapodia on the 

 left side 33 mm. Width as flattened in the shale 3 to 4 mm. One 

 parapodia is 3 mm. in length. Each one appears to be drawn in 

 towards the body. 



Observations. — ^^The unique specimen representing this species is 

 flattened and slightly distorted in the shale. The head is not as 

 distinct as the body and some of the posterior portion is missing. 

 In the hope of finding other specimens during the season of 19 ii 

 further discussion on its structure will be deferred. This species is 

 associated with Ottoia proliiica (pi. 29, figs. 1-5). 



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.) northeast 

 of Burgess Pass, above Field, British Columbia. 



CANADID.^;, new family 

 Polychaeta with a slender body formed of long segments bearing 

 setiferous parapodia with dorsal and ventral bundles of setse. Head 

 small with two strong tentacles. 



