54 



DEPTH 

 NUMBER 



STATIO^B 



PER 



DEPTH 



300 

 290 

 280 



i'ho 



260 

 2 50 

 240 

 230 

 220 

 210 

 200 



DEPTHS IN FATHOMS 



Fig. 15. Graphs of the number of species occurring at various increments of depths from shore 



to abyss, as compared to the number of stations occupied in the same depths. Species totals 



include both living and dead occurrences. 



crustaceans, but six times as many echinoid species in the northern than 

 the southern region. However, there were the same number of lamelli- 

 branch species, indicating that the catch effort for infauna was about the 

 same, but that the excess shell dredging in the northern region produced 

 more eplfaunal or motile forms than the grab sampling in the south. With 



