at Pensacola, they attained a peaJc rating of meditua heavy in 19^5^ merely 

 a trace In 19h6, and low in the slight rating in 19^7. At the Railroad 

 Trestle at the Naval Air Station, the attack rated the oarest trace in 

 19l<-5 and 19h6, with no forms showing in I9U7. Pholadldae occurred 

 sporadically at all three locations." At the Ferry Slip at the Naval Air. 

 Station the attack rated a trace in 19^^^ moderate In 19^5^ none In 19^6, 

 and medium heavy in 19^7. At the Ferry Slip at Pensacola they rated 

 slight in 19i«-5 and only a trace in 19^7, with no forms the other years. 

 At the Railroad Trestle at the. Naval Air Station there was only a slight 

 attack in 19^5 and no attacks the other years. 



b. Fouling Organisms . Silt, algae, and invertebrate ajilmals 

 belonging to 7 phyla contributed to the fouling of the panels. The latter 

 coorprlsed sponges, hydrolds and Metrtdlum, encrusting and filamentous 

 Bryozoa, annelid worms, barnacles, miscellaneous nonborlng mollusks,: and 

 tunicates. Of these organisms, barnacles occurred with the greatest fre- 

 quency and in the greatest abundance] hydrolds also, occurred with great 

 frecLuency. Encrusting Bryozoa and serpulld worms occurred with consider- 

 able frequency, and filetmentous Bryozoa occurred with a fair degree of fre- 

 quency at one locality. Qysters and Jingle-shells occurred with still less 

 frequency, while the occurrence of the other forms, as well as the algae, 

 was merely sporadic or occasional. 



Figures 5 and k are iUustrations of test panels which had been 

 submerged at Pensacola. The panel shown in figure 5 iia-s been attacked 

 severely by Teredo and moderately by Llmnoria , while the damage done to 

 the panel shown in figure it- was the work of Teredo alone. 



5. Recent Addenda . The attack by Teredinldae rated very heavy in 

 both 191^8 and 19^9 at the Naval Air Station Ferry Slip-. The Llmnoria 

 attack was moderate at this location in 19^8 and medium heavy the following 

 year. Pholads also were recorded as heavy at this plaxse in 19^8, but as 

 only a trace In 19'<-9. 



At the Pensacola Ferry Slip there was a very heavy onslaught 

 of Teredinldae in both 19^4-8 and 19i)-9. The Llmnoria attack was slight 

 at this point in 19lt-8 and was only a trace the following year. There was 

 a slight attack by Pholads In 19^8, but none appeared in 19^9. At the 

 Railroad Trestle, the Teredinldae attack rated very heavy both years, but 

 Llmnoria appeared as a trace only in 19^9. There was also a trace of 

 Pholads in 19k3. 



95 



