Il8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



One genus, Canadia. 



Observations. — For comparison with recent annelids we turn to 

 the Aphroditidse/ Amphinomidse, and Pahnyridse, but in none of 

 these do we find the slender body, narrow segments combined with 

 the small parapodia, and great development of setae without, scales 

 on the dorsal surface. 



CANADIA, new genus 



The description and illustrations of Canadia spinosa will serve to 

 indicate this genus. The other species express, in variations in size 

 and position of the bundles of setse, characters that for this prelimin- 

 ary study are considered to be of specific value. 



Genotype. — Canadia spinosa, new species. 



Strati-graphic 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. 



Observations. — Five species are referred to Canadia: C. spinosa, 

 C. setigera, C. sparsa, C. dubia, and C. irregularis. Of these the first 

 two are illustrated on pi. 23. The other three species will be illus- 

 trated in a final paper on this fauna. 



Generic name derived from Canada. 



CANADIA SPINOSA, new species 



Plate 23, figs. 4-7 



Body slender, formed of 20 to 21 segments that, when flattened 

 on the shale, are a little longer than wide ; each segment has a pair 

 of parapodia with a dorsal and ventral bundle of strong non-jointed 

 seta^. The setse are finely illustrated by figs. 4, 6, and 7. Head 

 minute, with a pair of large tentacles curving outward from the 

 front anterior margins ; a bundle of fine setre occurs on each side of 

 the head back of the base of the large tentacles. A straight slender 

 enteric canal is indicated on several specimens. Ivlouth and anus 

 not seen, but probably at or near the end of the annelid. 



Dimensions. — The largest adult specimen has a length of 34 mm., 

 with a width of the body at the seventh segment from the head of 

 1.5 mm. 



^ See Dr. E. Ehlers beautiful memoir on the annelids of the Blake expedi- 

 tion. Mem. Mus. Comp. ZooL, Vol. 15, 1887. 



