2. A lgae . Green algae occurred sporadically. A trace was 

 recorded on only one of the 56 control panels, and growths ranging from 

 traces to light were recorded on 8 of 36 test panels. 



5. Invertebrate animal phyla . 



a. Coelenterata (hydroids ). Hydroids occvirred as traces on 

 16 of the 56 control panels, and as traces to light or rarely moderate 

 growths on 30 of 36 test panels. Tubular la was the only form identified. 



b. Arthropoda (crustaceans ). Balanus ('bamacles) occurred 

 more or less abundantly on 10 of the 36 control panels; their development 

 on these panels was limited to the warmer months. One panel was kCf/i 

 covered. The maximum diameter of the bamacles recorded was 3 nm. They 

 occurred in greater abundance on 27 of the 36 test panels. The maximum 

 diameter recorded on test panels submerged for 8 months was 17 mm. Of 

 these panels, 15 were from 50^ to 1005^ covered. Araphipods (mostly 

 Corophiu m) occurred on k consecutive test panels removed at montlily 

 intervals from October 2, 19^5^ to February it-, 19^6, after having been 

 submerged for 8 months. The largest number of Corophium recorded on one 

 panel was 100. 



c. Mollusca (nonborin^ mollusks ). Miscellaneous mollusks 

 occurred sporadically on occasional panels. Mytilus (mussels) occurred 

 on il- of the test panels, the maximum number on any panel being 15, and 

 the maximum length recorded being 8 mm. A single specimen of Anemia 

 (jingle- shells), it- mm in diameter, was recorded on the last one of the 

 test panels. A few specimens of Saxicava were recorded on 2 of the test 

 panels and on one control panel, the maximum number on any panel being 8. 



Alt-. 05 ' SuTmrwry and Conclusions 



1. Installation . A test board of the panel type installed at the 

 U. S. Coast Guard Depot at Southwest Harbor, Mt. Desert Isle, Maine, on 

 December 2, 19Wt-, is still being operated. The results of the test have 

 been summarized to the end of 19i<-7. 



2. Test Results . 



a. Borers . Wo evidence of Teredinidae was recorded at this 

 location. Limnoria occurred with considerable regularity on the control 

 panels exposed during the warmer months of each year, but only in small 

 numbers. Limnoria occurred on all the test panels submerged after April 

 10, 19k0, but the attack rated only from a trace to slight throughout 

 the ^-jear period covered by the test except once in 19^6, when a peak 

 rating of moderate was attained. 



29 



