Il6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



by Mrs. Walcott in splitting a slab of shale that had been slid down 

 the mountain side and carried by pack animal to the Burgess Pass 

 camp. We were all greatly interested and every one was on the alert 

 to find other specimens. About ten days after the anterior half of 

 the specimen represented by figs, i and 2 was found Mrs. Walcott 

 called my attention to another " straight worm " she had found in a 

 slab that had been blasted out of the ledge and taken to camp after 

 the first discovery of the long annelid. I compared the two speci- 

 mens and found that the break across them was on the same angle 

 and that they fitted together to form the entire animal. Part of the 

 second find is shown by fig. 5. The two parts united are 26 cm. in 

 length. Subsequently several fragmentary specimens were found, 

 but nothing equal to the specimen so strangely and fortunately saved 

 by a most unusual combination of circumstances. 



There are a number of unsolved questions relating to this annelid 

 on which I will not now speculate, as the collection of 191 1 may give 

 further material for study, 



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

 member of the Stephen formation ; west slope of ridge between 

 Mount Field and Wapta Peak, one mile northeast of Burgess Pass, 

 above Field on the Canadian Pacific Railway, British Columbia, 

 Canada. 



AYSHEAID^, new family 



Polychseta with a slender fusiform body with many segments, 

 large, strong, segmented parapodia attached to alternating groups of 

 segments, setas on parapodia as hoops or jointed spines. Head small 

 with two and probably four tentacles. 



Observations. — It would be hazardous to define a family of living 

 Polychaeta from the data afforded by Aysheaia pedunculata, but it 

 would be still more so to identify this strongly marked form with 

 any of the described families. The peculiar segmentation of the 

 body and the attachment of the large parapodia on alternating 

 groups of segments are unusual. While it is not impossible, it is 

 not probable that a Cambrian annelid of this type would belong to 

 any of the families of recent annelids. 



AYSHEAIA, new genus 



Of this genus there is but one species and one specimen known. 

 The generic and specific descriptions are combined under the species. 

 Genotype. — Aysheaia pedunculata, new species. 



