are muddy, sandy, or mixed. The sea floor appears smooth 

 and nearly barren (Figure 3), but the presence of in- 

 numerable small hillocks, holes, and other irregularities 

 verify the existence of an abundant fauna which consists 

 mainly of different kinds of smaller metazoan animals. 

 An occasional five-rayed shallow depression is made by 

 an Astropecten , and the slender erect sticklike projections 

 are tubes of phoronids, onuphids, or the stiff stipe of a 

 sea whip. 



Animal associations of rocky or gravelly areas are 

 limited mainly to the upper slopes of Santa Monica Canyon, 

 as in the outer regions of Zone I„ Macrokelps, which 

 require shallow rocky surfaces for attachment of the 

 stipe, are mainly restricted to the northern areas of 

 Santa Monica Bay, A small triangular area (Zone II) 

 between the upper end of Redondo Canyon and the Palos 

 Verdes Hills, supports a diversity of kinds of animals 

 in unusual concentrations. The broad sandy shelf and 

 slopes of the western and northwestern end of Zone I 

 have concentrations of brittle stars requiring quiet 

 water. The bottom of Redondo Canyon below 300 feet 

 (Zone V) is overlain by muddy sediments which support 

 unique associations of animals having their greatest 

 known concentrations in this place. The fauna of Santa 

 Monica Canyon, below 300 feet (Zone IV) resembles that 

 of Zone V, but is more limited and dispersed. Analyses 

 of samples from ihese bottoms are given in the Appendix, 



