38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



6. Of these E. clavatum, B. frigida, and E. advena are most abun- 

 dant and usually comprise over 75 percent. 



7. E. clavatum is most abundant in near-shore areas (<20 m.), 

 whereas E. advena is most abundant in offshore areas (>20 m.). 

 B. frigida is abundant at depths of 10-40 m. 



8. These three abundant species can be used to construct a fora- 

 miniferal zonation of L.I.S. In the living population the mean depth 

 of stations in the Elphidium clavatum, Buccella frigida, and Eggerella 

 advena zones is 12 m., 25 m., and 29 m. respectively. The depth 

 ranges of these zones overlap. 



9. The size of the living population based on seasonal samples is 

 110 individuals per sample. At depths of 10-20 m. the living popula- 

 tion averages 177 individuals per sample, while in the 20-40-m. 

 range it averages 62. Miscellaneous shallow-water stations in the 

 0-1 0-m. range average 335 living individuals per sample. 



10. The E. advena zone of traverse 2 contained a significantly 

 greater number of living individuals than did traverse 3. 



11. The distribution of the total population closely approximates 

 that of the living population. 



SEASONAL SAMPLES 

 Introduction 



Traverse 3 was sampled seven times during the period June 1961 

 to November 1962 for the purpose of establishing whether or not 

 there is any seasonal variation in the living population. To do so, 

 the samples must be shown to be a reliable estimate of the number 

 of living Foraminifera at a given time. Table 2 shows that in the 

 near-shore areas (<20 m.) only two of the five sample pairs tested 

 have numbers of living individuals that can be considered to be from 

 the same distribution. In the offshore area (>20 m.) five of the 

 seven sample pairs tested indicate they are from the same distri- 

 bution. The offshore area, then, is more likely to give a better 

 estimate of the actual number of living individuals at a station. How- 

 ever, in the offshore area it is impossible to sample at exactly the same 

 location each time the traverse is sampled. Consequently, it is desira- 

 ble to treat the entire offshore area of traverse 3 as a single unit 

 or population. At any given time a sample of the living population 

 will be composed of several subsamples (stations). 



In order to test the reliability of this assumption, it was decided to 

 compare stations in the Eggerella advena zone at a given time. Five 



