NO. 2 



OLGA HARTMAN : SUBMARINE CANYONS 



29 



A diversified shelf fauna exists in 79 and 121 meters, as well as in 

 shelf depths with algal debris farther from shore. Some species attain 

 peak numbers; such are Aricidea lopezi with more than 310 individuals 

 per sample in 79 m, Ancistrosyllis tentaculata with 69 and Cossura 

 Candida with 86 in a sample. 



Axis depths, in 135 to 371 meters, have sediments of sand and 

 pebbles ; animals are almost entirely Capitella capitata subspp. in tre- 

 mendous numbers, with 14,145 individuals counted in a sample from 

 274 m (Hartman, 1961, p. 333); some harbor an endoparasitic 

 copepod, Monstrilla capitellicola (Fig. 11). At middle depths, in 517 



Fig. 11. Monstrilla capitellicola, a parasitic copepod, at left side, and 

 a parasite in the host species, Capitella capitata oculata, 

 at the right side, greatly enlarged. 



