36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



ZONATION OF THE TOTAL POPULATION 



Zonation of the total population using the same percent limits that 

 were used for the living population is shown in figure 18. The Buc- 

 cella frigida zone is now somewhat more extensive and the Eggerella 

 advena zone correspondingly more compressed. This is due to the 

 lower frequencies with which E. advena occurs in the total population. 

 This species is usually represented by only a few dead individuals, so 

 its percent in the total population depends heavily on the number of 

 living individuals. In general, the agreement between the zonation of 

 the living and total populations is quite good. The average depth of 

 stations in the E. clavatum zone based on the total population is 11m. 

 and the range 3-19 m. Stations in the B. frigida zone based on the 

 total population have an average depth of 26 m. and a range of 15-33 

 m. In the E. advena zone based on the total population the average 

 depth of the stations is 30 m. and the range 19-39 m. The mean 

 depth of stations in the E. advena and B. frigida zones is 1 m. deeper 

 than it was in the zonation of the living population, whereas the 

 mean depth of the E. clavatum zone is 1 m. shallower. The ranges 

 are more restricted except in the case of the B. frigida zone, where it 

 remained the same. 



Figures 14-16 show that the distribution of the abundant species 

 in the total population are comparable to their distributions in the 

 living population (figs. 5-7). The major difference is that in the 

 total population there is less accentuation of the species distribution, 

 that is, E. clavatum and B. frigida are more evenly distributed in the 

 deeper areas. It is likely that dead individuals of these species are 

 transported into deeper areas, and so the total population in these 

 areas has a higher percentage of them. 



Summary of the Distribution of the Foraminifera 



In summary the distribution of the Foraminifera has the following 

 characteristics : 



1. The fauna is composed of 23 species belonging to 15 genera. 



2. No planktonic Foraminifera were found. 



3. The number of species increases from west to east. 



4. Reophax dentaliniformis and R. nana are common in L.I.S. 

 but are not found in adjacent open ocean waters. 



5. The species Elphidium clavatum, E. pauciloculum, E. varium, 

 Buccella frigida, and Eggerella advena make up about 90 percent of 

 the total as well as of the living population. 



