the convex side of the 1-month panels. Colonial hydroids appeared 

 only from July though September, reaching their maximum attachment 

 rate in August. These organisms did not appear on monthly panels 

 exposed from October through June. Figure 10B shows the numbers 

 and lengths of colonial hydroids attaching to the convex side of panels 

 exposed for progressively longer periods of time.. As with the monthly 

 panels, colonial hydroids appeared first between July and August. 

 The number of colonies remained fairly constant, indicating that 

 setting took place only over a relatively short period of time, a fact 

 agreeing with data from the monthly panels. The growth, in terms 

 of the average length of the colonies, showed a rapid increase from 

 August through December with a sharp decline following. This is in 

 agreement with the report of Andrews (1953), which indicates that 

 hydroids attain dense woolly growth during late autumn and winter 

 and disappear during spring. Colonial hydroids were equally numerous 

 on both convex and concave sides. 



3. Calcareous Tubeworms 



Figure 11 shows the number of individuals and length of tubes 

 of calcareous tubeworms on the monthly and cumulative panels. 

 Tubeworm setting, as indicated by plots of the monthly panels (Fig. 

 11A), began in late June or early July and continued through October. 

 The greatest intensity of setting occurred in August; tubeworms 

 did not attach from November through June. The cumulative panels 

 (Fig. 11B) indicate that the number of individuals attaching to panels 

 increased until September and then remained essentially constant until 

 December. The rapid decrease in numbers of organisms occurring 

 after December may be attributed to the difficulty experienced in 

 counting them -when the total mass of fouling became large. Probably, 

 the actual numbers of tubeworms remained constant at about 700 

 per panel. More complete information probably will be forthcoming 

 from additional data. Tubeworms, as indicated by the average length 

 on the cumulative panels, made their most rapid growth during the 

 period July to September and exhibited virtually no additional growth 

 from October through March. 



4. Encrusting Bryozoans 



Plots of the total number and average diameter of encrusting 

 bryozoans on monthly and cumulative panels are shown in Figure 12. 

 The monthly panels, which indicate the degree of setting, showed 

 two periods of peak bryozoan activity (Fig. 12A). The first and greater 

 occurred during July, while the second and somewhat more moderate 



13 



