10 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 27 



(9) The San Diego trench, sampled only in its northern end 

 where bottoms were fairly uniform as to depth and sediment, con- 

 sistently contained only biological remains such as siliceous sponge 

 spicules, dead foraminiferans, dead mollusk shells and other animals. 



(10) La Jolla canyon contained the same kind of screenings as 

 the more southern Coronado canyon. At 79 and 976 meters, there 

 was fibrous debris; woody debris occurred in 371 and 637 m, plant 

 debris in 135, 274 and 517 meters. In its shallowest axes depths, the 

 animals were chiefiy those characteristic of lowered salinity. At its 

 middepths the animals were those found at shelf depths, accompanied 

 by much detritus ; at its lowest depths, the animals were those of an 

 abyssal fauna. 



(11) The Coronado canyon had dead shells in 177 and 344 m, and 

 flocculent debris in 566 m. 



In summary, therefore, all of the long-shore canyons are character- 

 ized by the presence of terrestrial debris or materials of noncanyon 

 origin. 



In contrast, the offshore canyons failed to show the presence of 

 detritus and woody debris as a screened residual. 



(12) The Santa Cruz canyon yielded pitchy lumps, in 676 m. 



(13) Catalina canyon yielded broken shells and blackened wood in 

 its shallowest or 88 m depth. 



(14) San Clemente rift valley had a hard, impenetrable bottom 

 and produced little in the way of samples or sediment. 



(15) Tanner canyon yielded biological debris, especially squid 

 beaks, conspicuous in 298 and 603 meters. 



Rocky bottoms were infrequent except in San Clemente, where 

 almost the entire canyon was rocky. In Santa Cruz canyon rocky 

 bottoms were encountered in 218 and 221 m. Samples coming from 

 these bottoms were generally unsatisfactory for quantitative analyses. 



MONTEREY CANYON 



This canyon is located far north of the others and was sampled 

 only during one cruise, when a few stations were made. It is included 

 in this series because there are interesting similarities in its benthic 

 fauna with that farther south. Biomass values are highest in 410 

 meters, at 255 grams per sample, and 260 m with 224 gm per sample; 

 they are lowest in 750 m with only 3 gm per sample. In 168 meters 



