DISCOVERY REPORTS 



SUMMARY 



The total number of benthic species for which the depth is recorded is 217, and of 

 these only 207 are used in the following analysis, the remainder being incapable of 

 inclusion in the chosen categories. These 207 species were caught in 770 hauls ; and if 

 we see how many species, and how many hauls belonging to these species, are confined 

 to any one of the given categories of depth, and, calculating what percentage they 

 constitute of the total number of species and hauls, compare them each with the others, 

 we may be able to form a rough estimate of the relative species density at the various 

 depths. In the following analysis the first three depth columns represent the same 

 categories as those in the preceding table ; the fourth column of the analysis, " 0-350 m.," 

 represents a combination of the first two columns of the table, i.e. species with repre- 

 sentatives both between o and 175 m. and between 175 and 350 m.; the fifth column 

 of the analysis, " 0-350 m. and below," represents a combination of all three columns of 

 the table, i.e. species with representatives between o and 175 m., between 175 and 

 350 m. and below 350 m.; the sixth column of the analysis, "Between 175-350 m. 

 and below," represents a combination of the second and third columns of Table III and 

 needs no explanation. 



Table III 



Depth 



It is noteworthy that for almost the same number of hauls (28 per cent, of the total 

 as against 27 per cent.) nearly three-fifths of the total number of species were confined 

 to above the 175 m. line, as against one-fifth with representatives both above and below 

 the 175 m. line. 



Pelagic species 



In Table IV, opposite, the bathymetrical range of the pelagic species is shown by the 

 arrangement in parallel columns of the minimum and maximum depths at which each 

 species was found. Where there is only one record, this is set down in the minimum 

 depth column. 



The sign (-0) after the depth indicates that the net, though fishing for the duration 

 of the station at the recorded depth, was hauled open to the surface. The possibility is, 

 therefore, not excluded that the organisms contained in it were caught during its passage 

 to a higher level. 



