14 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 22 



others. Most of the species found on these bottoms have their more ex- 

 tensive ranges along the continental slope areas of the eastern Pacific 

 and into cold shallower bottoms of the north Pacific Ocean. Some species 

 are like those found by the ALBATROSS in 1904. Others are unknown 

 to science, but their more extended ranges might be anticipated in the 

 eastern Pacific. A few are like those described from north Pacific deep 

 water (Uschakov, 1955, p. 287). 



The more distant basins, Tanner, West Cortes and San Clemente 

 are poorly known ; their known faunas are related only to those of the 

 eastern Pacific Ocean. 



There have been no typical cosmopolitan abyssal species, such as 

 those in the genera Laetmonice (aphroditid), Admentella, Drieschia, 

 Macellicephala and Intoshella (polynoids) or the quill-like tubes of Hya- 

 linoecia tubicola (Muller) (anonuphid). 



BIOMASS AND BIO-INDEX VALUES OF THE BASINS 

 COMPARED WITH THOSE OF ADJACENT AREAS 



Biomass, expressed as the weight of living organisms per unit area, 

 has been calculated for the samples collected in the basins (Table 1). 

 Some of the data were recorded as displacement volume while most of 

 them were direct weighings. The displacement data, in milliliters, were 

 converted equivalently to grams since the values are low and most 

 animals lack heavy skeletons. A number of samples were rechecked and 

 showed less than 5% difference between volumes and weights in units 

 of grams and milliliters. All of the samples from the basins have been 

 large, an indication that the full areal capacities of the grabs were 

 utilized ; the biomass data have been calculated on this basis, the orange- 

 peel-grab covering 0.24 square meter, the Campbell grab covering 0.55 

 square meter. 



Data from San Pedro and Santa Monica Basins were arranged to 

 include stations lacking life so that the biomass figures are an average of 

 all samples. The calculated figures from basins other than San Pedro, 

 Santa Monica and Santa Catalina are unreliable due to the sparse 

 sampling and may be modified with additional collections. 



The biomasses (or standing crops) of two of the nearshore basins 

 are quite low, about 4.0 to 5.0 grams per square meter. Analyses of the 

 other nearshore basin, Santa Barbara, show a much greater biomass, 

 approximately 42.0 grams per square meter. This is due to the fact that 

 two of the collected samples were at or near sill depths and a number 



