occurred more or less abundantly on 7 of the^^l control panels and on 

 10 of the 47 test panels. One of the control panels was covered. , 

 Bugula flabellata, B, nerltlna , and B. sp. were Identified. ^' 



c. Annelida (annelid worms ). Serpulld ( Serpula ) tubes 

 occurred on 5 of the kl control panels and on 10 of the kj test panels, 



the maximum on any test panel 1)61113 100, 



d. Arthropoda (crustaceans ). Balanus ('barnacles) occurred 

 on 5**- of the kl control panels and on 45 of the hf test panels. 

 Maximum diameters of 12 mm were recorded on the control panels, and 



of 18 mm on a test panel after 5 months' euhmergence . Six of the 

 control panels were from 25^ to 100^ covered, and 25 of the test panels 

 were from 20^ to 100^ covered. Barnacles, which developed every month 

 of the year at Mayport, may cover panels within a short period at any 

 season of the year. 



e. Mollusca (nontoring mollueks ). Miscellaneous nontorlng 

 moilusks occurred occasionally on the panels as follows: AnomJa 

 (jingle-shells) occurred on 5 of the panels of toth the control and 

 test series, the largest number on any one of the latter panels "being 

 25; Mytllue (mussels) occurred on 2 control panels and on 5 test panels, 

 the maximum on any one of the latter panels "being 20; Ostrea (oysters) 

 occurred on a single control panel and on 8 test panels, the largest 

 number on any one panel "being 55. A length of 58 mm was recorded on a 

 test panel sulimerged for 7 months. A solitary specimen of Mus cuius 

 lateralis occurred on one of the control panfti a . 



AI7.O5 Summary and Conclusions 



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

 at the tJ. S. Coast Ouard Training Station at Mayport, Florida, on 

 June 2, 19kh, is still "being operated. The results of this test have 

 "been summarized to the end of 19^7. 



2. Test Eesults . 



a. Borers . Teredlnldae were very active and destructive 

 throughout the period covered "by the test. Increasing the thickness 

 of the panels did not prolong their life; and in order to prevent 

 their unlnterpreta'ble destruction, it was found necessary to reduce 

 ttie period of su"bmergence to^ 5 months. Even control panels su'bmerged 

 for a single month, were eomet lines filled or riddled. The attack 

 rated very heavy each year, including 194it. Llmnoria were more or less 



85 



