14 



Journal of the Mitchell Society 



{^October 



TABLE 3. 



TABLE 4. 



60-65 



65-70 



70-75 



75-80 



The rareness of the occurrence may perhaps be better understood 

 when we realize that the numbers in these tables indicate the calcu- 

 lated number per liter, while the number actually observed was 1/40 

 of this. It is further show^i l)j a comparison of the number of these 

 with the total number of organisms in the collection. The best ratio 

 is 1:125, while the average is 1/350. 



There is insufficient data concerning the tides to determine whether 

 this is an ocean or bay form. 



