NO. 2 OLGA HARTMAN : SUBMARINE CANYONS 9 



animals ; they are more completely characterized at the ends of the 

 separate analyses, by canyon, station and depth data. Most of the 

 samples have yielded mud in greatest abundance. This passed through 

 the screens with ease when silty, and with difficulty when sticky. 

 The northern long-shore canyons contained a conspicuous amount 

 of consolidated mud balls or fecal pellets of sizes retained by the 

 finest (about a mm mesh) screen. Some of the other inert fractions 

 consisted of gravels, especially coming from some axes depths ; woody 

 and fibrous plant debris, possibly originating from the runoff of 

 rivers ; algal detritus, possibly from slumping of huge chunks of sedi- 

 ments to lower levels ; and dead remains of animals, such as mollusk 

 shells, squid beaks, fish otoliths, spicules of echinoderms and siliceous 

 sponges. 



(1) Monterey canyon, at 410 meters, showed considerable dead 

 shells of Dentalium (a scaphopod) and Amphissa (snail), whereas in 

 750 and '906 meters much woody debris was correlated with low 

 biological productivity, suggesting an upset condition, perhaps the re- 

 sult of seawater dilution. 



(2) Hueneme canyon had considerable flocculent debris and dead 

 Phyllospadix, a grass, in 98 meters, flocculent debris and gravel in 271 

 and 456 meters, and dead Dentalium and Amphissa shells in 478 and 

 621 meters. 



(3) Mugu canyon had shelly debris and dead sticks prominent 

 in 378 meters, and flocculent debris in 676 meters. 



(4) Dume canyon had blackened shells in 638, and blackened 

 plant debris in 71 1 meters. 



(5) Santa Monica canyon contained flocculent debris in 116 and 

 183 m, dead scaphopods {Dentalium) in 330 m and brown waxy lumps 

 in 463 m. 



(6) Redondo canyon, in axes depths, had black shelly sand with 

 odor of hydrogen sulfide in 137 and 148 m ; plant and woody debris 

 in 298 m, and very coarse sand in 560 m ; woody debris was en- 

 countered also in 715 m, or fan depths. 



(7) The San Pedro sea valley had blackened tubes and waxy 

 lumps with plant debris in 661 m, or its lower end. 



(8) Newport canyon had woody debris in its shallowest, 16 m 

 depth, much biological detritus in 36 and 97 m, and flocculent debris 

 in 478 m. 



