NO. 2 HARTMAN, BARNARD: BENTHIC FAUNA OF DEEP BASINS 233 



The latter two groups are difficult to segregate into lists of specific 

 components without considerable research into their reproductive 

 biology. 



SUGGESTIONS FOR FUTURE STUDY 



The borderland basins of southern California offer considerable 

 interest and what we have tried to present in this study is an initial 

 faunal compendium. The faunas of the various basins and groups of 

 them are strikingly different in many respects, despite the framework 

 of community similarity, and we envision the opportunity to approach 

 new studies on a larger scale, with more statistical precision. Because 

 of cost one cannot hope to sample the basins on such a close grid 

 system as has been done on the shelf, but there is great need for 

 more sampling. 



A program of sampling should be planned to assess each basin 

 by samples in proportion to its metric area, with some additional 

 samples in the smaller basins to provide a better cross section of 

 species. Each sample analyzed adds species in diminishing numbers. 

 On this basis, standing crop, species distribution and frequency could 

 be assessed statistically and related to some of the following factors: 

 depth, where the basins of the middle group provide depths of 1357, 

 1833, 1966 and 2107 meters, the outer basins 1551, 1769, 1938, 1979, 

 and 2571 meters; distance from shore, where basins of the middle 

 and outer groups could be compared, e.g., Santa Catalina, 1357 m, 

 with Tanner, 1551 m, Santa Cruz, 1966 m, with East Cortes, 1979 m. 



Perhaps it is wise to suggest that the area of the basin may 

 have some bearing on the faunas developed in it, with larger basins 

 offering better catchments due to larger amounts of larvae-bearing 

 water passing through them. On the other hand, smaller basins with 

 steeper sides might offer greater diversity in environment, particularly 

 in the grain size of sediments. 



The sills and ridges separating the basins need investigation as 

 possible supply points for some vegetative species, but it must be re- 

 membered that these shallower areas usually have coarser sediments, 

 so that the environments and the faunas are not comparable. It should 

 be expected that the banks have more species than the basins, since 

 epifaunas are known to be richer in species; but it is possible that total 

 standing crop and frequency of specimens on deep sills would be lower 

 than in the basins where food might collect through entrapment. 



