6 of the hi panels exposed > the greatest number in any one panel "being I5. 

 Most of these occurred in panels submerged during May and Jxuie of 15^5 

 and 19^6, and only one occurred in each of 2 panels submerged during 

 October 19^6 and August 19^7* respectively. Limnoria occurred in every 

 one of the test panels except the first 2, the attack attaining peaks 

 (1,500) vith low moderate ratings in paaels removed October 1, 19^5> and 

 December 1, 19^6, after having been submerged for 8 months. During 

 practically all of 19'*-7* hovever, the attack only rated a trace. 



A2,0k Fouling Agents 



1. Silt . Silt occurred as traces to occasionally light deposits 

 on all but one of the 4l control panels, and as traces to light or 

 occasionally moderate deposits on all the kl test panels. 



2. Algae. Traces of green algae appeared on only 8 of the control 

 panels, having developed only on those removed from June 1 to October 1 

 after having been submerged for 8 months. 



5. Invertebrate animal phyla . 



a. Coelenterata (hydrolds) . Hydroids occurred as traces on 

 8 of the control panels and as traces to light growths on all but 3 of 

 the kl test panels. Tubularia was the only form identified. 



b. Bryozoa (encrusting ajad filamentous ). Encrusting Bryozoa 

 were not present on the control panels but developed in small numbers on 

 12 of the kl test panels. Electra crustulenta and Tegella unicornis were 

 identified. Filamentous Bryozoa also were lacking on the control panels 

 but developed more or less abundantly on k of the ^1 test panels. Bugula 

 flabellata was identified on 2 panels. 



c. Arthropoda (crustaceans ). Balemus (barnacles) were absent 

 on the control panels and occurred on only 2 of the test pemels removed 

 July 1 in 1945 and 19^6, respectively. The first of these panels had 

 about 50 specimens ranging from embryonic to 2 mm in diameter, -vdiile the 

 second had only 5 Juvenile specimens. 



d . MolluBca (nonboring mollusks ) . A few specimens of 

 Mytilus (mussels) occurred on a single control panel removed October 1, 

 i9li.il.. Embryonic or minute specimens were numerous on k test panels 

 removed from September 1 to December 1, 19^, after having been sub- 

 merged for 2, 5> k, and 5 months, respectively Four other specimens with 

 a maximum length of I.5 mm were on the last panel removed December 1, 19^7- 

 Anomia (.jingle -shells) was absent on the control panels but occurred 

 sporadically on 8 of the test panels, ranging in number from a few to 

 numerous and being mostly minute in size. 



23 



