Icar percentage rllf f erence' and coefficient of variation (C.V.) for esiiirjted monthlv intingement 

 abundances c* selected specie* froe 1973 to 1974. Collection frequencies range froat seven (daily) 

 tc one collection per veek . 



For each species actual (daily) monthly Impingement counts were compared to an estimated tctal 

 different collection schedules. Mean difference equals Che average of these mean differences. 



