NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS 39 



of the ten stations in this zone on the traverse of March 1962 were 

 chosen at random for comparison with the remaining five. The ten 

 stations in the E. advena zone on the traverse of June 1962 were 

 subdivided in the same way. The next step was to test whether two 

 samples (five stations each) taken at the same time came from the 

 same population. The test statistic chosen was the distribution-free 

 Wilcoxon two sample test which was discussed earlier. 



Table 5 (page 80) shows the results of the Wilcoxon test on the 

 total living population and the living populations of Elphidium 

 clavatum, Buccella frigida, and Eggerella advena for the traverses of 

 March 1962 and June 1962. No significant R m value was obtained, 

 indicating that the two samples for March 1962 and the two samples 

 for June 1962 are from respective identical populations. 



Seasonal Variations in the Living Population 



Eggerella advena is the most abundant species in the E. advena 

 zone and therefore it was the most rigorously tested. The stations 

 in the E. advena zone at each sampling time are considered a sample 

 and the Wilcoxon two sample test was made on all the possible 21 

 pairs from the seven sampling times. The results are shown in table 

 6 (page 81). Frequency distributions for the mean number of total 

 individuals and the mean numbers of living Elphidium clavatum, 

 Buccella frigida, and Eggerella advena in the E. advena zone at the 

 seven sampling times are shown in figure 19. The number of living 

 E. advena in October 1961 was significantly greater than at any other 

 time with the exception of January 1962. During the winter of 1962 

 the number of living E. advena declined, and then in June 1962 

 there was a small maximum after which they declined to the signifi- 

 cantly lower levels of September and November 1962. The early 

 autumn maximum so pronounced in October 1961 was not observed 

 in 1962. 



The frequency distribution of Elphidium clavatum in the E. advena 

 zone shows a maximum in June 1962. Table 7 (page 81) shows 

 that June 1962 was significantly greater than September, November, 

 and March, 1962. No significant difference was found between 

 November and January 1962. 



The frequency distribution of Buccella frigida in the E. advena 

 zone has maxima in June 1961 and June 1962. Table 8 (page 82) 

 shows that June 1962 was significantly greater than September and 

 November 1962. None of the other pairs tested gave a significant 

 value. Examination of the stations of June 1961 indicates that the 



