36 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL. 27 



-Contour Intervals in meters. , 

 -Black dots indicate sampling' 



stations with depth in meters. ;' 

 -Hyphenated numbere indicate; 



numbers of species and speeimerts 



o 



o 

 o 



% 



\ 



'>>. 



± 



40' 



35' 



35: 

 30' 



Fig. 16. Tanner canyon, with contour intervals in meters. Black 

 dots indicate sampling stations with depth in meters. Hyphen- 

 ated numbers indicate numbers of species and specimens. 



reddish brown shale scraped from a hard bottom. Only the shallowest 

 sample is from an axis depth ; others are 3 to 53 meters above it. 

 Total numbers of species range from 32 to 48, and specimens from 

 125 to 375 per sample. The most abundant specifically are polychaetes, 

 then small mollusics, and the most numerous individuals are Amphi- 

 pholis pugetana, numbering 290 in a small sample. The largest in- 

 dividual is Brissopsis pacifica, from the shallowest sample, and 

 ophiuroids comprise the bulk in deeper parts of this canyon. Aniihals 

 from shallower parts resemble those in other offshore canyons. Unique 

 species are two polychaetes, Paralacydonia paradoxa and Pherusa cf. 

 collarifera, also known from the basin; Dacrydium pacificum; and a 

 slender sipunculid, perhaps Golfingia sp. 



COMPARISON OF SHELF AND CANYON FAUNAS 



One of the most conspicuous differences between shelf and canyon 

 faunas is the replacement of animal groups or genera or species from 

 shelf depths to canyons. Red ophiuroids, notably Amphiodia urtica. 



