NO. 2 OLGA HARTMAN: SUBMARINE CANYONS 51 



mollusks 7.0 



a sipunculid 4.0 



In 221 meters, with 7.08 grams: 



polychaetes 47.0% 



mollusks 41.0 



sipunculid 7.0 



pycnogonid and crustaceans 4.0 



In 459 meters, with 146.8 grams: 



brissopsids 89.0% 



polychaetes 5.4 



mollusks 4.6 



2 isopods 1.0 



In 676 meters, with 0.9 grams, chiefly 3 anemones, polychaetes and a 



nemertean, comprised the biomass. 



Weights were negligible in 623, 902, 1387 and 1624 meters, but 



life was present in all sampled depths and characterized by considerable 



hexactinellid sponge (not weighed) in 902 meters. 



Catalina canyon: — Sampled depths of 88 to 1272 meters showed a 



sharp drop in biomass after 88 meters, increased* again to 379 meters, 



and dropped thereafter to only 4.0 grams per sample, in the deepest 



part. The values are as follows : 



330.6 gm/ sq.m., in 88 m. 63.6 gm/ sq.m., in 559 m. 



267.2 gm/ sq.m., in 379 m. 38.0 gm/ sq.m., in 914 m. 



196.8 gm/ sq.m., in 362 m. 35.0 gm/ sq.m., in 549 m. 



1 18.4 gm/ sq.m., in 266 m. 8.5 gm/ sq.m., in 708 m. 



88.4 gm/ sq.m., in 216 m. 8.0 gm/ sq.m., in 1272 m. 



Weights were negligible in 853 meters, partly because the rocky 



bottom could not be recovered ; the same was the case in 708 meters. 

 Percentages of weights by major groups of animals are as follows: 



In 88 meters, with 165.3 grams: 



ophiuroids 64.5% 



holothuroids 19.0 



4 Travisia and other 



polychaetes 16.5 



In 216 meters, with 44.2 grams: 



polychaetes 69.0% 



mollusks 19.6 



ophiuroids 8.0 



sipunculids 3.4 



